IRREGULARITIES  OF  THE  TEETH, 


AND 


THEIR  TREATMENT. 


IRREGULARITIES  OF  THE  TEETH, 


AND 


THEIR  TREATMENT. 


BY 

EUGENE  S.  TALBOT,  M.D.,  D.D.S., 

PROFESSOR  OF  DENTAL  SURGERY  IN  THE  WOMAN'S  MEDICAL  COLLEGE;  LECTURER  ON  DENTAL 
PATHOLOGY  AND  SURGERY  IN  RUSH  MEDICAL  COLLEGE,  CHICAGO. 


WITH  152  ILLUSTRATIONS. 


PHILADELPHIA: 

P.   BLAKISTON,   SON  &  CO., 

1012  WALNUT  STREET. 

1888. 


Kntcrrd  iut-onling  to  Act  of  Congress,  in  the  year  1887,  by 

EUGENE  S.  TALBOT, 
In  tht-  Office  of  the  Librarian  of  Congress,  at  Washington,  D.  C. 


TO  MY 

TEACHER    AND     FRIEND, 
WALTER  S.  HAINES,  M.D., 

PROFESSOR  OF  CHEMISTRY,  RUSH  MEDICAL  COLLEGE,  CHICAGO, 

THIS  VOLUME 
IS  RESPECTFULLY  DEDICATED. 


PREFACE. 


In  presenting  to  the  profession  a  work  upon  the  irregu- 
larities of  the  teeth,  the  author  has  endeavored  to  keep  in 
view  the  marked  progress  that  has  been  made  in  this 
department  of  dental  science  within  the  past  few  years.  This 


ERRATA. 


Page  157.—"  Dr.  Magill's  Retainer"  should  read,  "Dr.  Guilford's 
Retainer." 

Cuts  Nos.  6,  19,  49  and  50  should  be  credited  to  Dr.  John  J.  R. 
Patrick,  Illinois  State  Dental  Society  Transactions  of  1884. 


In  that  portion  of  the  work  devoted  to  descriptive  anatomy 
and  to  physiology,  attention  is  given  to  those  tissues  only  that 
are  immediately  involved  in  the  study  and  correction  of  irreg- 
ularities. Each  subject  is  considered  in  the  order  in  which  it 
would  naturally  present  itself  to  the  mind  of  the  operator 
while  the  patient  is  before  him,  this  clinical  character  being 
deemed  by  far  the  best  for  a  work  of  this  kind.  In  the  treat- 
ment of  irregularities,  mechanical  laws  are  illustrated  and 
applied  in  the  simplest  manner  possible,  each  law  being 
applied  practically  to  a  case  of  irregularity;  this  method 

vii 


PREFACE. 


In  presenting  to  the  profession  a  work  upon  the  irregu- 
larities of  the  teeth,  the  author  has  endeavored  to  keep  in 
view  the  marked  progress  that  has  been  made  in  this 
department  of  dental  science  within  the  past  few  years.  This 
treatise  is  intended  to  embrace  all  that  is  necessary  to  a  clear 
and  practical  understanding  of  the  etiology  and  treatment 
of  dental  irregularities.  Our  knowledge  of  the  etiology 
of  the  various  deformities  of  the  teeth  has  hardly  kept 
pace  with  the  marked  advancement  in  the  methods  for 
their  correction,  and  this  fact  has  induced  the  author  to 
devote  considerable  attention  to  the  causes  of  such  con- 
ditions, while  due  consideration  has  been  given  to  the 
methods  of  treatment.  No  pretense  has  been  made  to 
cyclopa3dic  fulness,  inasmuch  as  it  is  believed  that  practi- 
cableness  and  conciseness  in  a  scientific  work  are  preferred 
by  the  profession  to  verbosity  and  minuteness  of  detail. 

In  that  portion  of  the  work  devoted  to  descriptive  anatomy 
and  to  physiology,  attention  is  given  to  those  tissues  only  that 
are  immediately  involved  in  the  study  and  correction  of  irreg- 
ularities. Each  subject  is  considered  in  the  order  in  which  it 
would  naturally  present  itself  to  the  mind  of  the  operator 
while  the  patient  is  before  him,  this  clinical  character  being 
deemed  by  far  the  best  for  a  work  of  this  kind.  In  the  treat- 
ment of  irregularities,  mechanical  laws  are  illustrated  and 
applied  in  the  simplest  manner  possible,  each  law  being 
applied  practically  to  a  case  of  irregularity;  this  method 

vii 


,-KKFACE. 


being  apparentlv  th,  ht«t  t»  impn*  the  principal  fea  u^  .„ 
heoU'  UMotorimgulwitouponthemmdofthe 


.         It  would  1*  obviously  impossible,  as  well  u  UK 
U»  „,  illu-t:  |N"iti"n  in  which  a  wedge,  scivw.  level 

or  «.*  nmv  In-  applunl  ;  but  the  author  has  endeavored 
np^al,  illustration,  u  pri.u^.le  or  lau 

that  tin-  siu.li.nl  will  be  able  to  exemplify  each  principle  in 
a  varidy  of  vq  -  Although  a  delicate  subject,  tin  matter 
of  fees  ia  necessarily  a  term  /V"//'"'/"  to  th«-  student,  ami  aa 
.MK-lirvnl  by  tin-  author  t»lH':i  matter  of  greal  import- 
ana-  to  In.th  juitinit  ami  oj>erator. 

Tlu>  author  has  endeavored  to  give  due  <-ivdit  to  th.-.- 
workrrs  in  tli.-  tit'M  «»f  orthi».lontia  that  havt-  contril.utcd 
t..  »t>  advaiKviiu-nt,  and  if  any  injusticr  has  b.vii  doiu-  it 
has  been  uninu-ntional.  Tin-  author  desires  to  acknowledge 
:ndrbt.-diu-*s  to  hr>.  <i.  Frank  I.y.Utoii.  \V.  W.  All[»<,rt, 
and  C.  Stoddard  Smith  for  valuable  su^e>tions,  and  aN.,  to 
th,-  S.  S.  Whitr  IVntal  Manufacturing  Company  tor  the  u-e 

of  many  \\.MM!,  utv 

Ki-..  s     -   TALBOT. 

- 

D«em>'-  e,  1—7 


CONTENTS. 


PART  I.— ANATOMY. 

CHAPTER  I. 

PAGE 

THE  SUPERIOR  MAXILLJE, 9 

THE  INFERIOR  MAXILLA, 14 

THE  SUPERIOR  ALVEOLAR  PROCESS, 17 

THE  INFERIOR  ALVEOLAR  PROCESS, 18 

ANATOMY  AND  PHYSIOLOGY  OF  THE  TEETH, 20 

DESCRIPTION  OF  THE  TEETH, 21 

THE  TEMPORARY  TEETH, 25 

CHAPTEE  II. 

OCCLUSION  OF  THE  TEETH, 27 

THE  CROWNS  AND  BOOTS, 29 

TEETH  IN  POSITION  IN  THE  MAXILLA, 29 


CHAPTER  III. 

ETIOLOGY  OF  IRREGULARITIES, 

IRREGULARITIES  OF  THE  TEMPORARY  TEETH,    .  . 
IRREGULARITIES  IN  THE  SIZE  OF  THE  PERMANENT  TKKTH.    .   .   . 
IRREGULARITIES  IN  THE  NUMBER  OF  THE  PERMANENT  TKKTH.    , 
IRREGULARITIES  IN  THE  ARRANGEMENT  OF  THE  PERMANENT 

"ti 
TEETH, 


CHAPTER  IV. 

40 

ACQUIRED  IRREGULARITIES,  . 

THE  CENTRAL  INCISORS, 

THE  LATERAL  INCISORS, 

THE  CUSPID  TEETH, 

ix 


COM  I  N  '-• 


46 


K-BMnr  W  IW  BEI-vnov-  ro  UBEnf LAIMI 'IK 

SSSSLmi^Tl*™- 

I  \KITtE*.  .    •  .">! 

THE  V^HAPED  AK.  M 

;  n   BABM  »  •  u  >  i-  '  ^v  •  •  '  '  "    ....... 

.     .  .  ^i-i>     uv    I 'Ho  I  '  >N<  •  1  I '      I'!'1  V  I  1"N     "r       in'- 
IBB*  58 

TKMIHIBABY  TEETH 

(•HAPTl-i:  \. 

i  ic  \i HUN  up  mi:  TKM- 


roBABY  TEETH  ^ 

gg 

|»H,lTKrHIOXOF  TIIK  Cl'TKU  .1  V\\'. 

rumw--  ":  •UVN-I      ^ 

iBBEUt  UABITIK*  <>K  THE  TEETH  "I 


PART  II.— TREATMENT. 

(  HA1TKR  I. 
THE  Ptorm  PKMOD  FOB  RBOI-LATIXO 

I»HY-1  v\|.   I'MllMl.H.H    \l    ClIANCiKS, "•"' 

KTIIETECTII :~ 

DKCAY  or  THE  TEETH 

OCCLCWOV  

•      •  


<  HAITF.l;    II. 


-i, 


iOXH  OF  THE  M"i  III.   AM'M"litl>  .............       82 

ftrt-iiY  or  TH*  MODELS,   ..................  ...     88 

ArrucATiox  01  •  i  ...................     93 


I-HAITKI;  in. 

Mia  n                     i:«  KS 97 

THE  I.rv-EB. 97 

99 

THE  IN-  i  INH-  PI  \\> 100 

THE  STBEW ...  101 


CONTENTS. 
THE  WEDGE,    .......... 


ELASTIC  FORCE,  .......... 

LIGATUEES,  .............. 

ELASTICITY  OF  METALS,   ........ 


CHAPTER  IV. 

CONSIDERATION  OF  THE  DIFFERENT  METHODS,    ...  113 

PATRICK'S  METHOD, 

FARRAR'S        "         

BYRNES'           •'         116 

COFFIN'S j2i 

AUTHOR'S                    . ].)(i 

PIANO-WIRE, .125 

SPREADING  THE  DENTAL  ARCH, 12g 

REGULATING  INDIVIDUAL  TEETH, 


CHAPTER  V. 

TREATMENT  OF  SPECIAL  FORMS  OF  IRREGULARITIES, 135 

ROTATING  TEETH  IN  THEIR  SOCKETS, 135 

THE  FARRAR  METHOD, 135 

GUILFORD'S  "          138 

THE  AUTHOR'S      " 139 

MOVING  CROWNS  AND  ROOTS, 140 

FORCED  ERUPTION  OF  THE  TEETH, 1  •!•.' 

THE  MATTESON  METHOD, 142 

THE  AUTHOR'S         "  143 


CHAPTER  VI. 

PROTRUDING  TEETH,  KINGSLEY'S, J 

"  "      FARRAR'S, 

PROTRUSION  OF  THE  INFERIOR  MAXILLA, • 

ALLAN'S  CASE, ] 

METHODS  OF  RETENTION  OF  THE  TEETH  AFTER  REGULATING 

KINGSLEY'S  RETAINERS, 

RICHARDSON'S        "         

RUBBER  PLATES  WITH  GOLD  BANDS  AND  BARS, 

FARRAR'S  RETAINERS, 

MAGILL'S  • 

THE  AUTHOR'S   "  

I  OF  TIME  REQUIRED  TO  RETAIN  THK  TEKTII  ix  I'i.  \<T,    .   .  . 


IRREGULARITIES 


OF 


THE  TEETH. 


PART  I-ANATOMY. 


CHAPTER  I. 

THE  SUPERIOR  MAXILLA. 

The  two  superior  maxillary  bones  form  the  whole  of  the 
upper  jaw.  Each  bone  presents  for  examination  a  body  and 
four  processes.  The  body,  containing  the  Antrum  Highmori- 
anum,  has  four  surfaces :  an  external  or  facial,  an  internal,  a 
posterior  or  zygomatic,  and  a  superior  or  orbital.  The  direc- 
tion of  the  facial  surface  is  forward  and  outward.  A  depres- 
sion, the  incisive  or  myrtiform  fossa,  situated  upon  the  facial 
surface  above  the  incisor  teeth,  gives  origin  to  the  depressor 
alse  nasi  muscle,  the  compressor  nasi  arising  external  to  and 
a  little  above  it.  The  canine  fossa,  situated  external  to  tin- 
incisive  fossa  and  separated  from  it  by  the  canine  eminence, 
is  deeper  and  longer  than  the  latter,  and  gives  origin  to  the 
levator  anguli  oris.  Above  this  fossa  is  the  infra-orbital 
foramen,  transmitting  the  infra-orbital  nerve  and  artery. ; 
above  this  the  lower  margin  of  the  orbit,  which  gives  parti 
attachment  to  the  levator  labii  superioris  proprius  ( 1-  ig. 
2  9 


JQ  ,BRK,.,  i.MMTIBB  OP  THE  TEETH. 

The  posterior  surface  looks  backward  and  outward  and 
for,,.  ,  ,rt  rfth«  n  somatic  fossa.     About  its  centre  are  seen 
\\l  opining  of  thepo-tenor  dental  canals,  which  transm* 
t|u.  posterior  d.-ntal  vessels  and  nerves.    At  the  lower  pa 
of  tL-urtace  is  the  nuurillary  tuberosity,  a  rounded  omi- 

„„„ f  bone,  especially  prominent  after  the  eruption  of  the 

wisdom  teeth,  articulating  on  tlie  inner  side  with  the  tuU 


Fio.  1. 


OUTCH 


MttMIVf  'OS* 


fOSTfltlOlt  OMTtt 
CtMALS 


MAXILLARY    TUBCROSITY 


HCU8PIOS. 


trfOU" 


<.-ity  of  tin-  jKilate  bone.  The  superior  or  orbital  surface, 
smooth  and  triangular,  forms  part  of  the  floor  of  the  orbit. 
Int.-rnally.it  i^  bounded  from  in  front  backward  by  the  lach- 
rxiiial  l."iic.  tin- .•-  planiim  of  the  ethmoid,  and  the  orbital 
process  of  the  palate  bone.  Externally,  it  has  a  rounded 
margin,  which  enters  into  the  formation  of  the  spheno-max- 
illary  fissure,  ami  in  front  it  is  bounded  by  a  |>art  of  the 


PART  I— ANATOMY. 


11 


orbit.  Commencing  near  the  middle  of  the  outer  border  of 
this  surface,  and  passing  forward,  is  the  infra-orbital  groove 
terminating  in  a  canal,  which  subdivides  into  two  branches' 
the  infra-orbital,  opening  just  below  the  margin  of  the  orl.it' 
and  the  anterior  dental  canal,  which  runs  into  the  anterior 
wall  of  the  antrum  and  transmits  the  anterior  dental  vessels 
and  nerves.  The  inferior  oblique  muscle  of  the  eye  arises 
from  the  anterior  and  internal  part  of  the  surface  (Fig.  2). 


FIG.  2. 


BONES  PARTIALLY  CLOSING  OR/f/CE  Of 


ANTRUM    MARKED   IN    OUTLINE 


ANTER.  NASAL 
SPINE 


BRISTLE  PASSCO 
THROUGH  ANTE. 
PALAT.  CANAl 


INTERNAL  SURFACE. 


The  internal  surface  forms  a  part  of  the  cavity  of  the  mouth 
and  a  part  of  the  outer  wall  of  the  nose,  the  two  parts  being 
separated  by  the  palatal  process.    The  superior  division  pw 
sents  the  opening  leading  into  the  antrum  of  Highmmv. 
the  upper  border  of  this  opening  are  several  irwgolai . 
ties  closed  in  by  the  ethmoid  and  lachrymal  bones 
mencing  near  the  middle  of  the  posterior  border  of 


\->  IRREGULARITIES    OF   THE   TEETH. 

and  running  downward  and  forward,  is  a  groove,  om- 
1  im,,  u  canal  (the  posterior  palatine)  by  the  articulation 
of  thi>  jH.rtion  of  the  bone  with  the  vertical  plate  of  tin-  pal- 
ate. Itclow  the  opening  is  a  concavity  forming  a  part  of  the 
inferior  im-atu*  »f  tin-  nose.  It  is  traversed  by  the  maxillary 
li-iirc.  whi.-li  receives  the  maxillary  process  of  the  palate 
A  deep  groove,  converted  into  a  canal  by  the  articu- 
lation of  the  lachrymal  and  inferior  turbinated  bones  i-  Bit- 
uated  in  front  of  the  opening  of  the  ant  rum.  It  is  called  the 
lachrymal  or  nasal  duct.  Anterior  to  this  is  the  inferior  tur- 
l.inat.'  which  articulates  with  the  inferior  turbinated 

IK.HC.  Above  this  crest  is  a  part  of  the  middle  nn-atus.  and 
In-low  it  a  part  of  the  inferior  mcatus  of  the  nose.  The  infe- 
rior division  of  this  surface  i<  rough,  and  has  several  small 
opening-  for  the  passage  of  nutrient  vessels. 

The  antrum  of  Highmore  is  a  triangular-shaped  cavity, 
funded  by  the  four  surfaces  of  the  body  of  the  bone  and  by 
the  alveolar  process,  and  with  its  base  toward  the  internal 
surface.  ( >n  the  latter  surface  is  the  irregular  opening  of  the 
antrum.  which  is  nearly  closed  in  the  articulated  >kull  by 
the  approximation  of  the  ethmoid,  inferior  turbinated  and 
palate  b<.; 

On  the  posterior  wall  of  the  antrum  are  the    posterior 
dental  canals,  and  on  its  floor  are  seen  several  conical  pro- 
•  u<.  corn-ponding  to  the  roots  of  the  molar  teeth. 

The  Malar  Process  is  a  rough  eminence  situated  at  tin 
junction  of  the  facial  and  zygoma  tic  surfaces.  It  is  concave 
in  front  and  behind,  articulates  above  the  malar  bone,  and 
below  is  marked  by  a  ridge  which  separates  the  facial  from 
the  /ygomatic  Mirface.  The  Xasal  Process  is  situated  at  the 
>ide  of  the  nose  and  extends  upward,  inward  and  hack- 
ward.  Its  external  surface  is  smooth  and  concave,  and  gives 
attachment  to  the  levator  labii  .superioris  ala^ne  nasi.  the 
orbicularis  palpchrarum  and  tendo-oeuli  nuiM-les.  and  is 
jK-rforated  by  several  foramina.  The  internal  surface  articu- 
lates above  with  the  frontal,  and  has  a  rough  surface,  which 
closes  in  the  anterior  ethmoid  cells;  below  this  are  seen,  from 


PART   I — ANATOMY.  13 

above  downward,  the  following  points  of  interest :  the  supe- 
rior turbinated  crest,  a  part  of  the  middle  meatus  of  the 
nose,  the  inferior  turbinated  crest,  and  a  part  of  the  inferior 
meatus. 

The  anterior  border  is  directed  obliquely  downward  and 
forward,  and  articulates  with  the  nasal  bone ;  the  posterior 
border  presents  a  groove  for  the  lachrymal  duct,  and  has 
two  margins,  the  inner  articulating  with  the  lachrymal  bone, 
and  the  outer  forming  a  part  of  the  circumference  of  the 
orbit. 

The  Palatal  Process  projects  inward  from  the  internal 
surface  of  the  bone. 

It  is  a  strong  process,  thicker  in  front  than  behind,  and 
forms  a  large  part  of  the  roof  of  the  mouth  and  of  the  floor 
of  the  nose.  Its  upper  surface,  smooth  and  conical,  presents 
in  front  the  upper  orifice  of  the  anterior  palatine  canal, 
situated  just  behind  the  incisor  teeth  and  transmitting  the 
anterior  palatine  vessels.  The  naso-palatine  nerves  pass 
through  the  inter-maxillary  suture. 

The  inferior  surface,  rough  and  uneven,  is  perforated  by 
numerous  foramina  for  .the  passage  of  nutrient  vessels.  At 
the  back  part,  near  the  alveolar  border,  is  a  longitudinal 
groove  (sometimes  a  canal),  which  transmits  the  posterior 
palatine  vessels  and  large  nerves.  The  lower  orifice  of  the 
anterior  palatine  canal  may  be  seen  on  this  surface.  In 
some  bones  may  be  seen  a  delicate  suture,  which  marks  out 
the  inter-maxillary  bone  ;  this  comprises  that  portion  of  the 
upper  jaw  which  contains  the  incisor  teeth.  The  outer 
border  of  this  process  unites  with  the  body  of  the  bone- 
The  inner  border  unites  with  the  bone  of  the  opposite  side, 
and  the  two  form  a  groove  on  the  upper  surface  for  the 
reception  of  the  vomer.  The  anterior  border  is  prolonged 
forward  internally  to  form  the  anterior  nasal  spine.  The 
posterior  border  articulates  with  the  horizontal  plate  of  the 
palate  bone. 


14 


I  U  REGULARITIES   OF   THE   TEETH. 


TMI-:  iM'i:i;ioi;  MAXILLA. 

Tin-  inferior  maxillary  bone  (Fig.  3)  consists  of  a  body  and 
two  mini.  The  body  is  horizontal,  and  curved  like  a  horse- 
shoe, and  presents  for  examination  two  surfaces  and  two 
borders.  The  external  surface,  convex  from  side  to  side,  j .r< - 
M-nis  in  its  median  line  a  vertical  ridge,  the  symph\ 
which  indicates  tin- junction  of  the  two  pieces  of  which  tin- 
bom-  consists  in  early  life;  this  ridge  terminates  below  in  an 
eminence — the  mental  process.  Just  external  to  the  sym- 
physis.  ami  below  the  incisor  teeth,  is  the  incisive  fossa,  for 


Fio.  8. 


M'O*. 


the  attacbnit-nt  of  the  levator  menti  muscle.  Kxtcrnul  to 
this,  and  just  below  the  second  bicuspid  tooth,  is  the  menial 
foramen,  through  which  pass  the  mental  nerves  and  artery. 
Extending  outward  from  the  base  of  the  mental  pro- 
the  external  oblique  line,  at  first  nearly  horizontal,  bul  after- 
ward inclining  upward  and  backward.  It  is  continuous  with 
the  anterior  border  of  the  minus,  and  affords  attachment  to 
the  depiv— <ir  labii  inferioris  and  depressor  anguli  oris, the 
platysma  myoides  being  inserted  below  it.  The  internal 


PART    I ANATOMY. 


15 


surface  (Fig.  4)  presents  on  each  side  of  the  median  line 
and  just  below  the  centre  of  the  bone,  two  tubercles  called 
the  genial  tubercles.  The  upper  pair  gives  attachment  to  the 
genio-hyoglossi  muscles,  and  the  lower  pair  to  the  genio- 
hyoidei  muscles.  External  to  the  genial  tubercles  is  an  oval 
depression  for  the  reception  of  the  sublingual  gland.  The 
anterior  belly  of  the  digastric  muscle  is  attached  to  a  rough 
depression  below  the  sublingual  fossa.  The  internal  oblique 
line  commences  at  the  back  part  of  the  sublingual  fossa.  It 


FIG.  4. 


MYLO-HYOIO  RIDCE 


is  especially  prominent  opposite  the  last  two  molars,  and 
affords  attachment  throughout  its  entire  length  to  the  mylo- 
hyoid  muscle.  The  superior  constrictor  of  the  pharynx  is 
attached  to  the  alveolar  margin  of  this  surface  near  the  last 
molar  teeth.  Below  the  ridge  is  an  oblong  depression,  the 
submaxillary  fossa,  for  the  reception  of  the  submaxillary 
gland.  The  inferior  border  of  the  body  is  rounded,  and  at 
its  junction  with  the  ramus  presents  a  shallow  groove,  over 


16  IRREGULARITIES    OF  THE  TEETH. 

which  the  facial  artery  turns.  Kach  of  the  perpendicular 
portions  or  rami  presents  for  examination  two  surfaces,  four 
borders  and  two  processes.  The  external  surface  is  flat  and 
gives  attachment  to  the  masseter  muscle.  The  internal  <ur- 
face  presents  near  its  centre  the  opening  of  the  inferior 
dental  canal. 

On  the  posterior  margin  of  this  aperture  is  a  prominent 
ridge,  to  which  is  attached  the  internal  lateral  ligament  of 
the  lower  jaw.  At  the  lower  and  back  part  of  the  opening 
is  a  notch  leading  into  a  groove  (the  mylo-hyoidean),  which 
runs  downward  and  forward  to  the  suhmaxillary  fossa.  Thi- 
groove  lodges  the  mylo-hyoidean  vessels  and  nerves.  The 
internal  pterygoid  muscle  is  inserted  into  a  rough  >urfai •»• 
behind  this  groove. 

The  inferior  dental  canal  runs  downward  and  forward,  in 
the  suhstance  of  the  bone,  as  far  as  the  incisor  teeth,  when  it 
turns  to  communicate  with  the  mental  foramen  ;  it  contains 
the  inferior  dental  vessels  and  nerves. 

The  lower  border  of  the  ramus  is  continuous  with  the  body 
of  the  bone.  The  junction  of  the  inferior  and  posterior  hol- 
ders of  the  ramus  forms  the  angle  of  the  jaw;  it  is  marked 
l>y  rough  ridges  on  both  sides,  the  masseter  muscle  being 
attached  externally,  the  internal  pterygoid  internally,  and 
the  stylo-maxillary  ligament  between  the  two  mii-des.  The 
anterior  border  is  continuous  with  the  external  oblique  line. 
The  posterior  border  is  thickened,  rounded  and  covered  hv 
the  parotid  gland. 

The  superior  border  presents  two  processes,  an  anterior  or 
coronoid  and  a  posterior  or  condyloid.     The  coronoid  pro- 
cess is  a  thin,  triangular  eminence  of  bone,  which  gives 
attachment  on  either  side  to  the  temporal  muscle.     On  the 
internal    surface  is  the  commencement  of  a   ridge  which 
extends  to  the  posterior  part  of  the  alveolar  process.    On  tin 
outer  side  of  this  ridge  is  a  deep  groove,  wlii  eh.  with  the  rid. 
•rives  attachment  above  to  the  temporal  and  below  to  the 
buccinator  muscle. 

The  condyloid  process  consists  of  two  portions,  the  condyle 


PART   I — ANATOMY. 


17 


and  neck.  The  long  axis  of  the  condyle  is  transverse, 
and  the  outer  extremity  is  a  little  higher  than  the  inner.  It 
is  oblong  in  form,  the  articular  surface  extending  farther  On 
the  posterior  than  on  the  inferior  surface.  The  neck  presents 
externally  a  tubercle  for  the  attachment  of  the  external  lat- 
eral ligament.  The  anterior  surface  is  concave,  and  has 
attached  to  it  the  external  pterygoid  muscle.  The  posterior 
surface  is  curved. 

THE  SUPERIOR  ALVEOLAR  PROCESS. 

The  alveolar  processes  comprise  the  larger  part  of  the 
lower  borders  of  the  superior  maxilla?  and  the  upper  border 
of  the  inferior  maxilla.  The  alveolar  process  of  each  supe- 
rior maxilla  includes  the  tuberosity,  and  extends  as  far 
forward  as  the  median  line  of  the  bone,  when  it  articulates 
with  the  process  upon  the  opposite  side.  It  is  narrow  in 
front,  and  gradually  enlarges  until  it  reaches  the  tuber- 
osity, where  it  becomes  rounded  upon  itself. 

If  we  examine  the  two  articulated  superior  maxillary  bones 
(Fig.  5),  we  see  that  the 
anterior  part  is  curved, 
while  the  posterior  part 
gradually  diverges  from 
the  central  line  of  ossifi- 
cation of  the  maxillary 
bones.  The  shape  varies 
in  different  individuals. 
Some  arches  are  small 
and  others  large ;  the  arch  is  parabolic  in  some  cases  and 
circular  in  others. 

The  process  is  composed  of  two  plates  of  bones,  an  outer 
and  an  inner,  which  are  united  at  intervals  by  septa  of  can- 
cellous  tissue.  These  form  the  alveoli  for  the  reception  of 
the  roots  of  the  teeth.  The  outer  plate  is  thinner  than  the 
inner.  In  some  cases  the  buccal  surfaces  of  the  roots  of 
healthy  teeth  extend  nearly  or  quite  through  the  outer 
bony  plate. 


18  IRREGULARITIES    OP  THE   TEETH. 

This  plate  is  continuous  with  the  facial  and  zygomatic 
-urfaces  of  the  maxillary  bone.  The  inner  plate  is  thicker 
and  stronger  than  the  outer,  and  is  fortified  by  the  palate 
1  Mines.  The  external  plate  is  irregular  upon  the  outer 
surface,  prominent  over  the  roots  of  the  teeth,  and  depre--ed 
between  the  roots  or  interspaces. 

The  prominence  over  the  canine  teeth,  called  the  canine 
eminence,  is  very  marked,  and  decidedly  modifies  the 
expression  of  the  face.  The  sockets  of  the  central  incisors 
are  conical  and  round,  those  of  the  lateral  incisors  conical 
and  slightly  flattened  upon  their  mesial  and  distal  snrt'a 
and  not  so  large  as  the  central  sockets. 

The  pit  for  the  cuspid  is  conical  and  much  larger  than 
any  of  the  other  sockets.     The  sockets  for  the  bicuspids  are 
flattened   upon   their   anterior  and  posterior   surfaces,  and 
near  the  apex  they  are  frequently  bifurcated.     The  socl 
of  the  molars  are  large  at  the  openings,  but  at  about  the 
middle  of  their  length  they  are  divided  into  three  smaller 
sockets  for  the  reception  of  the  roots.     In  the  ease  of  the 
third  molar  the  number  of  sockets  ranges  from  one  1. 
cavity  to  three  or  four  of  smaller  size. 

THE  INFERIOR  ALVEOLAR  PROCESS. 

The  alveolar  process  of  the  inferior  maxilla  extends  from 
the  ramus  of  one  side  to  the  same  point  on  the  other.  The 
outline  is  similar  to  that  of  the  superior  process,  the  anterior 
portion  being  much  thinner. 

The  description  given  of  the  structure  of  the  superior  pro- 
cess will  also  apply  to  the  inferior.  The  outer  plate  of  hone 
opposite  to  the  molars  and  bicuspids  is  thicker  than  the 
inner  plate,  while  the  inner  plate  opposite  the  canines  and 
incisors  is  thicker  than  the  outer. 

The  alveoli  are  arranged  along  the  border  of  the  hoi. 
the  reception  of  the  roots  of  the  teeth.     They  correspond  in 
form  to  the  roots  which  they  accommodate.     The  alveoli  lor 
the  central  incisors  are  smaller  than   those  for  the  lateral. 
They  are  conical  in  shape,  and  flattened  upon  their  mesial 


PART   I — ANATOMY.  19 

and  distal  surfaces.  Those  for  the  lateral  incisors  are  larger, 
and  compressed  on  their  mesial  and  distal  surfaces.  The 
sockets  for  the  canines  (cuspids,  or  stomach  teeth)  are  larger, 
deeper  and  less  compressed  than  those  for  the  incisors. 

The  sockets  of  the  bicuspids  are  considerably  flattened 
upon  their  lateral  surfaces,  and  are  sometimes  divided  into 
two  cavities.  The  sockets  for  the  anterior  roots  of  the 
molars  are  broad  and  flattened  laterally,  while  those  for  the 
anterior  roots  are  round.  The  third  molar,  being  naturally 
of  variable  form,  has  sometimes  one  pit,  and  again  three 
or  four.  Each  alveolar  pit  or  socket  is  divided  from  its 


FIG.  6. 


neighbor  by  a  small  wall  or  septum,  which  is  made  up  of 
cancellated  bone,  extending  about  one-eighth  of  an  inch 
above  the  inner  and  outer  plate. 

The  dental  septa  assist  in  keeping  the  teeth  firmly  in  their 
places. 

Fig.  6  illustrates  an  internal,  lateral  section  of  the  lower 
jaw,  showing  the  relation  of  the  alveoli  and  the  septa — a,  a,  a, 
dental  septa — b,  b,  b,  dental  root  septa.  It  will  be  observed 
that  the  septa  are  very  thin  at  the  margin,  and  gradually 
increase  in  width  to  the  middle  of  the  jaw,  where  they 


20  IRREGULARITIES  OF   THE   TEETH. 

l.ecomc  thicker,  and  are  finally  lost  in  the  substance  of 
the  jaw.  Some  septa  are  thicker  than  others,  and  where 
two  teeth  an-  \\  idely  separated,  the  width  of  the  septa  nat- 
ural lv  corresponds  to  the  space  between  the  teeth. 

The  sockets  an-  lined  with  a  thin  plate  of  compact  bony 
substance,  extending  from  the  outer  and  inner  plate  of  the 
alveolar  process  to  the  apex,  where  there  are  small  opening 
for  the  entrance  of  nerve  and  blood  vessels  for  the  nourish- 
ment of  the  teeth. 

This  bony  plate  has  upon  its  inner  surface  the  ela-tie 
peridental  nieinl.rane,  which  acts  as  a  cushion  for  the  teeth. 
while  upon  the  inner  surface  it  is  surrounded  by  .-p"ii.i:y 
bone. 

\\ATOMY  AND  PHYSIOLOGY  OF  THE  TEETH 

The  Teeth  are  classified  as  temporary  and  permanent. 
The  former  term  is  applied  to  those  erupted  in  infancy. 
which  are  small  and  delicate,  to  meet  the  requirements  of  the 
child.  The  permanent  teeth  are  of  a  larger  and  stronger 
growth,  to  meet  the  demands  of  adult  age. 

The  Temporary,  deciduous  or  milk  set  consists  of  twenty 
teeth,  ten  in  each  maxilla,  viz.:  two  central  incisors,  two 
lateral  incisors,  two  cuspids  and  four  molars. 

The  Second  or  permanent  teeth  number  32,  sixteen  in 
each  maxilla,  viz.:  two  central  incisors,  two  lateral  incisor-. 
two  cuspids,  four  bicuspids  and  six  molars.  For  convenience 
of  description  a  tooth  is  divided  into  a  crown — that  part 
which  is  exposed  in  the  mouth — a  root  or  roots,  situated  in 
the  alveolar  process,  and  a  neck,  the  part  connecting  the 
crown  witli  the  root.  It  is  also  divided,  according  to  the 
tissues  of  which  it  is  composed,  into  the  enamel,  dentine, 
cementuin,  and  pulp. 

The  Enamel  (Fig.  7,  A)  is  the  hardest  structure  of  the 
human  body.  It  forms  a  smooth,  dense,  external  layer  on 
the  teeth,  and  serves  as  a  cap  or  covering  to  preserve  tin- 
dentine  of  the  crown;  it  is  thickest  at  the  cutting  and 
grinding  edges  of  the  tooth,  and  gradually  diminishes  in 
thickness  until  it  reaches  the  neck,  where  it  disappears. 


PART    I ANATOMY. 


21 


FIG.  7. 


It  is  nearly  inorganic  in  structure,  containing  but  from  one 
to  three  per  cent,  of  animal  matter. 

The  Dentine  (B),  which  constitutes  the 
largest  part  of  the  tooth  and  gives  it  its 
shape,  is  an  ivory-like  substance  composed 
of  tubuli  surrounding  a  cavity  called  the 
pulp  chamber. 

The  dentine  is  in  many  cases  very  sen- 
sitive. Its  surface  is  entirely  covered  by 
enamel  and  cementum.  The  latter  forms 
the  osseous  covering  of  the  root  portion  of 
the  dentine,  being  thickest  at  the  apex  and 
gradually  thinning  out  toward  the  neck 
of  the  tooth  (c).  It  is  a  bony  substance, 
receiving  its  nourishment  through  the 
peridental  membrane,  which  latter  also 
nourishes  the  dentine  through  the  struc- 
ture of  the  cementum. 

Occupying  the  chamber  in  the  crown, 
and  the  canals  in  each  of  the  roots  of  the 
teeth,  is  the  pulp  (D),  consisting  of  a 
mucoid,  gelatinous  mass  permeated  by  blood-vessels  and 
nerves,  which  nourish  the  dentine.  The  peridental  mem- 
brane covers  the  root  of  the  tooth,  and  together  with  the 
periosteum  forms  a  cushion  between  the  alveolar  process 
and  the  root  of  the  tooth,  thus  preventing  irritation  to  the 
parts  during  mastication.  It  is  very  vascular,  and  sends 
numerous  blood-vessels  into  the  cementum  for  the  nourish- 
ment of  the  tooth. 

DESCRIPTION  OF  THE  TEETH. 

For  convenience  of  reference  the  different  surfaces  of  the 
crowns  of  the  teeth  are  designated  as  follows : — 

1st.  The  labial,  signifying  the  surface  nearest  the  lips. 
(This  applies  only  to  the  six  anterior  teeth.) 

2d.  The  buccal,  the  part  nearest  the  cheek  and  the 
buccinator  muscle. 


22 


IRREGULARITIES    OF   THE   TEETH. 


3d.  The  palatine,  tin-  surface  of  the  upper  teeth  next  to 
the  hard  palate. 

1th.  The  lingual,  or  that  part  of  the  lower  tooth  nearest 
the  tongue. 

~>t\\.  The  anterior  and  posterior  in  the  bicuspids  and 
molars,  the  mesial  and  distal  surfaces  in  the  case  of  tin- 
six  anterior  teeth. 

6th.  The  cutting  edges  of  the  incisors  and  cuspids  and 
the  grinding  surfaces  of  the  bicuspids  and  molars. 

The  incisors  (Fig.  8,  Nos.  1  and  2)  are  so  called  from  tl ie  La t  i n 
word  iitcido  (to  cut),  their  sharp  edges  fitting  them  for  cutting 
off  such  portions  of  food  as  may  be  required  for  mastication. 
They  act  on  the  same  principle  as  a  pair  of  shears.  They 


are  classed  as  Central  and  Lateral,  the  central  inci-ors 
the  larger.  Both  are  concave  on  their  lingual  surfaces  and 
convex  on  their  labial :  they  are  broader  at  the  cutting  edge 
than  at  the  neck. 

The  Left  central  is  distinguished  from  the  right  by  the 
mesial  angle  being  a  right  angle,  while  the  distal  angle  is 
slightly  rounded.  The  root,  when  normal,  is  straight, round 
and  conical.  Occasionally  it  is  slightly  flattened  upon  its 
mesial  and  distal  surfaces,  and  is  frequently  bent  at  the  end, 
the  apex  being  directed  toward  the  lateral.  The  roots  of 
the  laterals  are  shorter,  and  have  about  two-third-  the 
diameter  of  the  ceim-als. 

The  Canine  teeth  (Fig.  8,  No.  3),  or  eu-pids.  are  so  called 


PART    I ANATOMY.  23 

from  the  Latin  cuspis  (a  spear),  because  they  terminate  in  a 
point  adapted  to  the  purpose  of  seizing  and  tearing  flesh. 
They  are  convex  upon  the  labial  surface  and  slightly  con- 
cave upon  the  lingual.  The  canines  of  the  opposite  sides 
are  distinguished  by  the  mesial  angles  being  shorter  than 
the  distal,  thus  directing  the  tooth  toward  the  median 
line. 

Each  cuspid  tooth  has  a  single  conical  root,  sometimes 
round  and  sometimes  flattened,  always  larger  than  the  roots 
of  the  other  teeth  and  occasionally  bent  and  inclined  toward 
the  posterior  tooth. 

The  Bicuspids  (Fig.  8,  Nos.  4  and  5)  are  so  called  from 
their  peculiar  shape  (bis,  two,  and  cuspis,  a  spear).  The  two- 
spear  or  bicuspid  teeth  are  known  as  the  first  and  second 
bicuspids.  The  crowns  are  rounded,  and  a  groove  through 
the  centre  divides  the  grinding  surface  into  two  cusps,  the 
outer  being  the  longer.  The  angles  differ  in  length,  the 
anterior  being  shorter  than  the  posterior,  thus  indicating 
the  side  of  the  mesial  line  to  which  the  tooth  belongs.  Their 
roots  are  flattened  upon  the  anterior  and  posterior  surfaces, 
and  frequently  there  is  but  one  root,  with  a  groove  extending 
its  entire  length.  Owing  to  the  close  resemblance  between 
the  crowns  of  the  first  and  second  bicuspids,  it  is  difficult  to 
distinguish  them  except  in  the  mouth. 

The  Molars  (Fig.  8,  Nos.  6,  7  and  8)  (from  moleri,  to 
grind)  are  three  in  number,  viz. :  first,  second  and  third.  The 
crowns  are  cuboidal  in  shape,  with  from  three  to  five  tuber- 
cles or  cusps,  separated  by  grooves.  The  crown  of  the  first 
molar  is  the  largest.  The  upper  molars  have  three  roots, 
one  upon  the  inner  surface,  called  the  palatine  root,  which 
is  conical  in  shape,  very  long  and  round,  and  two  upon  the 
buccal  surface,  an  anterior  and  posterior.  The  anterior 
buccal  root  is  flattened  upon  the  anterior  and  posterior  sur- 
faces, and  is  larger  than  the  posterior.  The  roots  diverge, 
the  palatine  being  the  less  prominent,  which  makes  it  very 
easy  to  locate  the  tooth  as  belonging  upon  either  the  right 
or  left  side  of  the  mouth.  Frequently  the  roots  of  the  third 


24 


IRREGULARITIES   OF   THE   TEETH. 


molar  unito,  forming  a  single  root,  slightly  curved  to \vanl 
tlir  hueeal  Mirfaer  of  tin-  jaw. 

The  l..\ver  hi.-isnrsiKig.  -:i.  tfos.  i  and  2)  are  not  so  large 
as  the  superior  incisors.  The  lahial  and  lingual  surfaces 
are  straightcr  than  tin-  eonvsj>oiiding  surfaces  of  the  supe- 
rior incisors,  while  'the  mesial  and  distal  angles  are  1-oth 
right  angles.  The  laterals  are  broader  than  the  centrals, 
whieli  is  just  the  reverse  of  the  superior  incisors,  and  tin- 
roots  are  single,  conical,  flattened  upon  their  mesial  and 
distal  surfaces,  and  grooved  longitudinally. 

The  ( 'usj.ids  (No.  3)  are  slightly  convex  upon  their  labial 
surfaces  and  somewhat  concave  upon  the  lingual  .-urfaees. 
their  crowns  terminating  in  a  point.  Each  of  them  has  a 


Fir,.  9. 


single  root,  which  is  longer  than  any  of  the  roots  of  the 
inferior  teeth,  conical  in  shape,  but  slightly  flattened  upon 
the  mesial  and  distal  sides,  and  inclined  toward  the  first 
bicuspid. 

The  Bicuspids  (Xos.  4  and  5),  two  in  number — a  first  and 
.-eeond — are  situated  posterior  to  the  cuspids;  they  have 
round  crowns,  which  are  rather  concave  upon  their  grinding 
surfaces,  and  a  groove  running  through  the  centre  divides 
the  crown  into  two  parts,  a  buccal  and  a  lingual  cu-p. 
Unlike  the  superior  bicuspids,  the  outer  cusp  is  the  larger 
and  re-en ihles  the  cuspid  tooth,  while  the  lingual  cu-j>  is 
small,  being  sometimes  scarcely  developed. 

The  second  bicuspid   is  larger  than   the  first  and  more 


PART    I — ANATOMY. 


25 


spherical  in  shape.  The  roots  are  single  and  more  or  less 
flattened  on  their  mesial  and  distal  surfaces,  and  smooth, 
with  a  deep  groove  running  through  their  entire  length. 

The  Molars  (Nos.  6,  7  and  8)  have  large  crowns,  with  two 
roots  and  five  cusps,  three  buccal  and  two  lingual,  the  ante- 
rior cusps  being  the  larger. 

The  second  molar  has  four  cusps,  wrhich  are  divided  by  a 
crucial  depression.  The  third  molar  has  also  four  cusps, 
but  they  are  less  distinct  than  those  of  the  second  molar. 

The  anterior  root  of  these  teeth  is  broad  and  flattened 


FIG.  10. 


upon  its  mesial  and  distal  surfaces,  while  the  posterior  root 
is  rather  oval.  The  roots  of  the  third  molar  are  never  uni- 
form, being  sometimes  short,  sometimes  long,  separate  or 
fused  together,  straight  or  curved  towrard  the  angle  of  the 
jaw. 

TEMPORARY   TEETH. 

Iii  general  .outline,  these  teeth  resemble  the  permanent 
teeth.  The  crowns  are  much  smaller  than  their  namesakes 
in  the  permanent  set,  and  the  roots  are  larger  in  proportion 
than  those  of  the  permanent  set.  The  pulp  chambers  in  the 


26  IRREGULARITIES  OF   THE  TEETH. 

temporary  teeth  an-  aU>  larger  in  proportion  to  the  size  <>f 
tin-  tooth.  In  other  n-pecN  the  crowns  of  the  incisors  ami 
cu>pids  resemble  those  of  tin-  permanent  set  so  closely  that 
further  description  is  unnecessary. 

Tin-  molars  resemble  tin-  permanent  molars  as  regards 
their  grinding  surfaces  ami  general  outline,  but  are  mneh 
smaller,  being  from  one-half  to  two-thirds  the  size  of  tin- 
permanent  molars.  Occasionally,  it  is  difficult  to  distinguish 
them:  but  when  other  resources  tail,  an  unfailing  way  of 
determining  to  which  set  the  tooth  belong-  i-  to  carry 
tin-  point  of  an  excavator  down  along  the  buccal  surfa.-. 
until  it  reaches  the  gum.  If  it  be  a  temporary  molar,  tin- 
instrument  will  suddenly  fall  into  the  neck  of  the  tooth, 
win-re  the  enamel  stops  abruptly;  while,  if  it  be  a  perma- 
nent tooth,  the  instrument  will  gradually  glide  down  tin- 
enamel  until  the  neck  is  reached,  the  enamel  of  tin-  perma- 
nent tooth  gradually  tapering  to  a  thin  edge.  The  roots  of 
the  temporary  molars  resemble  those  of  tin-  permanent 
in  form,  but  diverge  considerably  to  admit  the  crown-  of  the 
permanent  teeth  between  them. 


CHAPTER   II. 

THE   OCCLUSION   OF   THE   TEETH. 

The  teeth  of  man  have  a  fixed  normal  relation  to  one 
another,  and  a  position  in  the  jaw  which  best  adapts  them  for 
the  purpose  intended,  i.  e.,  that  of  cutting,  triturating  and 
grinding  food. 

It  is  easy  to  determine  to  what  class  an  animal  belongs 
by  examining  the  shape  of  the  teeth  and  the  articulation. 
When  in  normal  position  the  teeth  are  in  close  contact,  and 

FIG.  11. 


serve  as  a  support  to  each  other,  like  the  stones  in  an  arch. 
The  arch  of  the  teeth  varies  as  much  in  nations  and  indi- 
viduals as  do  other  racial  characteristics.  The  size  and 
shape  of  the  arch  affect  the  appearance  as  much  as,  or  more, 
than  any  of  the  features.  For  instance  :  a  small  face  with 
a  wide-spreading  arch  would  be  a  great  detriment  to  beauty, 
or  the  association  of  a  large  face  with  a  narrow  arch  would 
result  in  a  face  entirely  devoid  of  beauty  so  far  as  features 
are  concerned. 

27 


28  IRREGULARITIES   OF   THE   TEETH. 

The  outline  of  .tlu-  juvh  naturally  depends  upon  predomi- 
nating characteristic^  ;  the  Englishman,  for  example,  with 
tin-  round,  large  head,  having  a  correspondingly  large  arch 
(Kg.  Hi. 

Figure  12  illustrates  the  typical  arch  ot  the  American 
woman,  narrow  aii«l  small.  1  Jet  \\ven  these  typical  examples 
«•!'  the  two  extremes  range  all  of  the  intermediate  grade>  of 
characteristic  arches.  These  arches  are  perfect  in  contour, 
ami  vet  neither  can  he  taken  as  a  standard  hy  which  to 
regulate  all  teeth.  Judgment  must  be  used  in  deciding 
these  points  before  beginning  an  effort  to  change  the  shape 


«i.  12. 


of  the  arch  or  the  position  of  the  teeth.  The  teeth  are 
arranged  in  the  alveolar  process  along  the  border  of  the 
superior  and  inferior  maxilla-  in  such  relation  to  each  other 
as  to  form  an  arched  contour.  When  the  jaws  come  together, 
the  superior  set  occlude  outside  of  the  inferior  teeth,  demon- 
strating the  fact  that  the  superior  arch  describes  the  segment 
of  a  larger  circle  than  the  inferior.  The  superior  centrals 
are  wider  than  the  inferior  centrals,  so  that  they  extend  over 
a  part  of  the  inferior  laterals.  The  upper  laterals  cover  the 
remainder  of  the  lower  laterals  and  a  part  of  the  lower 
cuspid.  The  superior  cuspid  covers  the  posterior  half  of  the 


PAET   I — ANATOMY.  29 

inferior  cuspid,  and  the  anterior  half  of  the  first  lower 
bicuspid,  and  the  relation  of  the  two  sets  continues  in  the 
same  proportion  to  the  end  of  the  arch. 

By  this  arrangement  of  "  breaking  joints,"  each  tooth  is 
antagonized  by  two  in  the  opposite  jaw.  This  is  an  import- 
ant fact  when  a  tooth  is  lost,  as  those  remaining  are  held  in 
position  by  the  occlusion  of  the  teeth  opposite,  and  so  retain 
their  usefulness. 

THE  CROWNS  AND  ROOTS. 

Ill  studying  the  teeth,  it  will  be  observed  that  the  charac- 
teristic teeth  of  the  stout,  thick-set  man  are  those  with  crowns 
broad  and  short,  and  roots  long  and  firmly  set  in  the  jaw  ; 
while  the  teeth  of  the  tall,  slender  person  are  characterized 
by  narrow,  long  crowns  and  very  short  roots. 

Teeth  with  long  roots  and  short  crowns  require  more  force 
in  regulating,  and  less  progress  is  made  than  with  teeth  hav- 
ing long  crowns  and  short  roots.  Care  must  be  exercised  in 
distributing  the  force  with  teeth  having  short  roots,  to  pre- 
vent their  being  pushed  out  of  their  sockets.  The  roots  are 
more  liable  to  be  deformed  than  the  crowns  ;  they  may  be 
bent  or  twisted,  enlarged  at  the  apex,  divergent  or  adherent, 
or  the  root  or  roots  may  be  in  contact  with  roots  'of  other 
teeth,  and  sometimes  extra  roots  are  attached.  All  these 
abnormal  conditions  tend  to  complicate  operations. 

THE  TEETH  IN  POSITION  IN  THE  MAXILLAE. 

The  teeth  are  held  firm  in  their  alveolar  sockets  by  a 
union  called  gomphosis,  which  resembles  the  attachment  of 
a  nail  in  a  board.  Teeth  with  one  conical  root,  and  those  with 
two  or  more  perpendicular  roots,  are  retained  in  position  by 
an  exact  adaptation  of  the  tissues.  Teeth  having  more  than 
one  root,  and  those  bent  or  irregular,  receive  support  from 
all  sides  by  reason  of  their  irregularity.  The  teeth  are 
also  held  in  position  by  the  peridental  membrane  (situated 
between  the  alveolar  process  and  the  root),  by  the  blood  ves- 
sels at  the  apices  of  the  roots,  and  by  the  gum,  the  tissues  of 


30 


IRREGULARITIES   OF   THE   TEETH. 


which  an-  continuous  with  those  of  the  mucous  and  peri- 
dcntal  iiieinKranes.  Fig.  13  illustrates  the  position  of  the 
teeth  in  the  jaws.  The  peridental  membrane  lines  the  alve- 
olus and  covers  the  roots  of  the  teeth.  It  is  a  fibrous  tissue. 
which  admits  of  a  slight  motion  to  the  teeth,  an- 1  art-  MS  a 
cushion  to  protect  the  jaws  from  severe  blows  ami  coneus- 
while  in  the  act  of  tearing  and  grinding  food. 

teeth  are  in  such  close  proximity  that  a  rul ^ »er  < la n i 
or   floss  silk  cannot  he  inserted   hetween   them  without  con- 


Flii.  13. 


sidera hie  pressure.  This  tissue  is  so  elastic  that  teeth  that 
have  Keen  forced  slightly  apart  will  return  to  their  normal 
portion  when  they  have  Keen  relieved  from  pivs.-ure. 

This  membrane  is  nourished  both  by  a  branch  of  the 
artery  which  passes  through  an  opening  in  the  jaw  and  the 
apex  of  the  root  and  by  arteries  passing  through  the  alveolar 
process  and  mucous  membrane  at  the  neck  of  the  tooth. 

The  nerve  supply  is  derived  in  a  similar  manner. 


CHAPTER  III. 


ETIOLOGY  OF  IRREGULARITIES. 
IRREGULARITIES  OF  THE  TEMPORARY  TEETH. 

Irregularities  of  the  temporary  teeth  rarely  occur,  because 
of  the  fact  that  in.  their  development  they  meet  no  obstruc- 
tions in  the  jaws.  They  are  so  small,  and  the  growth  of  the 
jaw  is  so  rapid,  that  the  teeth  have  abundance  of  room. 
Absorption  and  reproduction  of  bone  go  on  rapidly  at  this 
period,  and  the  crypts  containing  the  teeth  being  located 
near  the  surface  of  the  bone,  the  teeth  pass  through  without 
difficulty. 

The  alveolar  process  is  regularly  formed,  excepting  an 
occasional  irregularity  from  some  freak  of  nature.  When 
irregularities  do  occur,  they  are  frequently  the  result  of 
thumb-sucking  or  some  similar  cause,  or  of  the  inharmo- 
nious development  of  the  jaws.  The  habit  of  thumb-sucking 
must  manifest  itself  during  the  retention  of  the  first  set  of 
teeth,  as  it  is  acquired  from  the  fifth  to  the  eighteenth  month, 
and  the  temporary  teeth  erupt  about  this  time.  Irregulari- 
ties from  thumb-sucking  are  never  uniform.  They  may  be 
located  in  the  centre  of  the  jaw  or  upon  either  side,  depend- 
ing upon  the  hand  used,  and  the  thumb  or  finger  inserted. 
The  teeth  of  either  jaw 
may  be  prevented  from 
erupting,  or  the  process 
from  developing,  by  the 
pressure  of  the  thumb. 
Fig.  14  will  illustrate  the 
case  of  a  child  six  years 
old,  who  contracted  the 
habit  at  about  the  tenth 
month.  It  will  be  observed 
that  the  teeth  of  both  jaws 
have  erupted  to  nearly  or  quite  their  normal  length,  notwith- 

31 


Fi 


32  IRREGULARITIES   OF   THE  TEETH. 

standing  tin-  piv--mv  produced  by  closing  the  jaws  upon  the 
thumb.  The  maxillary  bones,  however,  have  been  retarded 
in  growth.  The  teeth  of  tin-  inferior  maxilla  do  not  articu- 
late properly  with  those  of  the  superior  maxilla,  which  is 
caused  by  the  thumb  rotating  after  the  jaws  are  closed,  thus 
throwing  the  lower  jaw  to  the  left. 

The  hard  palate  was  flat  and  normal,  showing  that  the 
pn-«.inv  was  direct  upon  the  teeth,  and  that  the  thumb  did 
not  come  in  contact  with  the  ti—ues  of  the  mouth.  The 
superior  jaw  and  teeth  may  be  brought  forward  by  absorption 
and  deposition  of  bone,  and  the  lower  teeth  and  jaw  carried 
backward  in  the  same  manner  by  pressure  of  the  thumb 
(Fig.  1 "»).  The  inferior  maxilla  may,  by  this  cause,  be  car- 

Fio.  15.  1  i...  16. 


ried  backward  and  the  angle  be  a  right  angle  instead  of  an 
obtuse  one.  In  thumb-sucking  the  arch  takes  the  oval  shape 
ratlin-  than  the  sharp  angle  called  the  V-shaped  arch,  unle— 
the  teeth  project,  in  which  case  they  have  the  fan-shaped 
appearance.  In  the  irregularity  known  as  the  prognathous 
or  under-hung  jaw,  shown  in  Fig.  16,  the  anterior  teeth  of 
the  lower  jaw  project  beyond  those  of  the  upper.  This  is  sup- 
posed to  be  an  inherited  deformity.  It  seems,  rather,  to  be 
the  result  of  inharmonious  development  of  the  superior  and 
inferior  maxillary  bones;  the  rami  of  the  jaw  do  not  as-ume 
the  proper  angle  with  the  bo.lv  at  a  proper  time  in  life,  or 
the  rami  are  longer  in  proportion  to  the  body  or  to  the 
superior  maxilla. 


PART  I — ANATOMY.  33 

It  is  not  advisable  to  correct  irregularities  of  the  temporary 
teeth,  as  the  jaws  are  expanding  rapidly  and  the  teeth 
remain  but  a  few  years.  The  appearance  of  the  first  teeth 
has  no  effect  upon  the  permanent  teeth,  and  is  no  indication 
of  the  shape  or  position  of  the  second  set.  This  fact,  if 
impressed  upon  the  minds  of  parents,  would  relieve  the 
minds  of  many. 

IRREGULARITIES  IN  THE  SIZE  OF  THE  PERMANENT  TEETH. 

By  comparing  the  teeth  of  the  present  generation  with 
those  found  in  skulls  from  one  to  three  thousand  years  old, 
it  will  be  observed  that  the  size  of  teeth  have  altered  very 
slightly.  Teeth  are  generally  regular  in  size ;  occasionally, 
however,  may  be  seen  excessively  large  crowns  in  the  central 
incisors  of  the  upper  jaw,  and  in  rare  cases  we  find  one 
incisor  larger  than  the  other.  Such  deformities  are  neces- 
sarily conspicuous.  When  the  crowns  are  unnaturally 
large  the  roots  are  usually  short  and  stunted,  and  cen- 
trals with  large  crowns  are  usually  associated  with  small 
laterals.  The  laterals,  however,  are  seldom  larger  than 
normal. 

When  the  cuspids  exceed  the  normal  size  they  affect  the 
expression  of  the  face  more  than  any  of  the  other  teeth, 
giving  great  prominence  to  the  features  and  a  resemblance 
to  the  carnivora.  The  bicuspids  and  molars  are  usually 
normal  as  to  size.  The  teeth  more  commonly  fall  below  the 
average  size  than  exceed  it,  which  fact  is  particularly  appli- 
cable to  the  lateral  incisors  and  wisdom  teeth. 

When  the  laterals  are  abnormally  small,  they  assume  a 
conical  shape,  the  extremely  small  ones  resembling  the 
teeth  of  the  cat.  When,  as  is  sometimes  seen,  the  follicles 
of  two  teeth  unite,  the  result  presents  the  appearance  of 
a  single  tooth,  the  roots  of  which  are  divided,  and  this  is 
the  only  means  of  showing  the  preexistence  of  two  separate 
teeth. 


34  Ii:i;i.(.I  I.UMTIES  OP  THE   TEETH. 

iKm:«. ri. \UITIKS  IN  THI:  NTMMKR  OF  THE  FKI;M  ANTAT 

TEETH. 

Tho  normal  number  of  permanent  teeth  is  thirty-two,  hut 
from  various  causes  tin-  full  complement  is  not  nlway- 
reached,  and.  on  the  uth.T  haiid.it  is  sometimes  exceeded. 
We  cannot  amve  with  Tomes  and  Salter,  who  claim  that 
when  an  irregularity  in  nuiiilHT  exists  it  is  more  likely  to 
.-•1  than  fall  below  this  number. 

When  there  are  more  than  the  normal  number,  the  super- 
fluous teeth  are  calle  1  supernumerary  teeth.  They  may 
iv-emMe  the  natural  teeth,  or  may  take  a  form  perfectly 
rou ml  ami  conical,  with  short  root,  or  the  crown  is  flattened 
and  the  catting  edge  serrated.  Supernumerary  teeth  which 
arc  similar  to  any  of  the  natural  teeth  generally  roemble 
the  incisors  or  molars.  We  have  never  seen  a  second  canine 
or  a  third  bicuspid  upon  only  one  side  of  the  jaw.  Mr. 
Salter  has  observed  two  canines  in  one  individual,  and  one 
example  of  a  supernumerary  bicuspid  tooth. 

When  the  central  or  lateral  has  a  supernumerary  of  a 
.-imilar  form  by  its  side,  it  is  usually  difficult  to  distinguish 
the  normal  from  the  supernumerary,  the  latter  bein^  nearly 
perfect  in  form.  The  lateral  incisor  is  more  commonly 
duplicated  than  the  central.  Wisdom  teeth  are  sometime- 
accompanied  by  a  supernumerary,  in  which  case  there  will 
be  four  molars  upon  one  side.  When  the  temporary  teeth 
remain  in  connection  with  the  permanent  ones,  they  arc 
not  clashed  as  supernumerary  teeth. 

The  conical  and  serrated  supernumerary  teeth  are  usually 
found  as-ociated  with  the  incisors  or  wisdom  teeth.  When 
found  in  connection  with  the  incisors,  they  are  cither  situated 
between  the  central  incisors  or  in  the  palatine  surface  pn— 
terior  to  the  incisors.  When  joined  with  the  \vi<d«»m  teeth 
they  are  usually  upon  the  buccal  surface,  but  occasionally 
upon  the  palatine  surface,  and  sometimes  posterior.  Such 
teeth  are  the  result  of  an  extra -epithelial  cord  and  dental 
follicle.  Alienee  of  permanent  teeth  is  common,  and  c. 
are  recorded  in  which  permanent  teeth  never  erupted.  Lin- 


PART    I ANATOMY. 


35 


derer  reports  the  case  of  a  woman  fifty  years  of  age  who  never 
had  a  permanent  tooth.  Mr.  Tomes  relates  similar  cases, 
but  he  has  never  met  with  a  case  in  which  the  permanent 
teeth  were  all  wanting.  Cases  are  on  record  in  which  one 
central  incisor  was  missing,  but  these  are  of  rare  occurrence. 
Commonly,  we  find  one  or  both  laterals  missing,  also  one  or 
both  of  the  cuspids.  They  may  be  imbedded  in  the  jaw,  or 
their  follicles  may  never  have  existed.  If  they  are  in  the 
jaw  a  tumor  will  generally  locate  their  position,  and  may  be 
outlined  by  the  finger. 

Fig.  17,  taken  from  the  cast  of  a  girl's  mouth  twenty  years 
of  age,  illustrates  a  case  with  normal  teeth  missing.     She  is 


FIG.  17. 


under  my  treatment  at  present.  The  laterals  and  bicuspids 
of  the  upper  jaw  and  the  bicuspids  of  the  lower  jaw  are 
missing.  When,  as  is  sometimes  seen,  the  temporary  teeth 
are  in  the  place  and  do  the  duty  of  the  permanent  teeth, 
they  are  found  most  frequently  in  the  'following  order: 
1,  the  cuspids ;  2,  molars,  and  3,  lateral  incisors. 

The  wisdom  teeth  do  not  appear  at  all  in  many  mouths, 
while  in  others  some  of  them  only  are  erupted.  Prof. 
Winchell,  in  his  lecture  upon  "  The  Degeneracy  of  Man," 
states  that  the  early  races  were  invariably  supplied  with 
four  wisdom  teeth,  and  concludes  that,  since  they  do  not 
always  appear,  and  are  so  prone  to  disintegration,  this 


36  IRREGULARITIES  OF  THE  TEETH. 

is  a  strong  link  in  his  chain  of  proof  of  the  degeneracy  of 
man.  Other  late  writers  >how  strong  evidence  that  the 
wisdom  teeth  are  more  perfect  and  common  in  existing  than 
in  early  ra<-. 

I>r.  .1.  K.  Van  Marter,  in  his  study  of  prehistoric  d.  nti<try 
among  the  skulls  of  Umbrian  and  Ktru>ean  races  which 
existed  500  B.  c.,  says:*  "In  the  photo  marked  N...  1.  the 
teeth  were  exceedingly  fine  in  form  and  preservation.  In 
No.  '2,  the  teeth  were  equally  line,  hut  only  twenty-eight  in 
mini  her,  with  no  trace  or  sign  of  there  ever  having  he.  n 
thirty-two.  In  the  other  skulls  I  noted  the  same  want  of 
the  third  molars.  Evidently,  they  were  never  developed. 
It  is  worthy  of  note  that  in  the  comparatively  few  remain- 
of  prehistoric  skulls  in  the  above  collection,  there  should  he 
>uch  a  proportion  of  those  in  which  the  third  molar  does  not 
appear.  About  one-fourth  of  the  third  molars  were  wanting. 
What,  then,  becomes  of  the  theory  that  the  wisdom  teeth  aiv 
becoming  rudimentary  and  disappearing?  iVrhap-  they 
di-appeared  once  before,  and  reappeared  again  in  an  age  ..f 
wisdom,  but  are  now  fading  away,  marking  a  decadence  in 
that  dental  evidence  of  sage  understanding." 

iRRE(;uL\KTrn:s  i\  THE  ARRANGEMENT  OF  THE  PERMA- 
NENT TEETH. 

At  the  age  of  six  years,  the  temporary  teeth  and  the  tir-t 
permanent  molars  are  in  their  places  in  the  jaw.  I5y  remov- 
ing the  outer  plate  of  bone  in  the  jaw.  it  will  be  seen  that 
the  germs  of  the  permanent  teeth  are  in  their  crypt-,  a- 
is  shown  in  Fig.  18.  While  the  teeth  grow  independ- 
ently of  the  alveolar  processes,  the  processes  depend  to  a 
great  degree  upon  the  teeth  for  development.  \Vith  t! 
various  conditions  existing  at  the  same  time,  it  i<  not  sur- 
prising that  the  teeth  are  erupted  out  of  a  normal  position. 

The  alveolar  processes  are,  to  a  certain  extent,  independ- 
ent of  the  jaws.  The  parts  below  the  mental  foramen  on 

*  Iml<  i»  ml,  nl 


PART    I — ANATOMY. 


37 


the  lower  jaw,  and  above  the  palate  on  the  upper  jaw,  are 
hard  and  dense,  and  are  for  the  attachment  of  muscles. 
The  alveolar  processes,  composed  of  soft  and  yielding  tissue, 
are  expressly  for  the  purpose  of  the  formation  of  the  teeth 
while  in  the  crypts,  and  for  their  retention  after  they  have 
erupted.  When  the  teeth  are  removed,  the  processes  are 
absorbed,  and  nothing  remains  in  old  age  but  the  dense  bone. 
In  intra-uterine  life,  while  the  teeth  are  forming,  the 
alveolar  processes  cover  and  protect  the  crypts  in  which  the 
germs  are  located,  and  as  they  grow  and  force  their  way 


FIG.  18. 


through  the  processes,  absorption  takes  place  and  most  of 
the  bone  vanishes.  After  they  have  passed  through,  depo- 
sition of  bone  again  takes  place  for  the  purpose  of  holding 
them  firmly  in  place.  Again,  these  teeth  are  shed  and  bone 
is  absorbed  to  admit  the  second  set  of  teeth,  after  which  new 
material  is  deposited  for  their  retention.  This  is  the  case 
under  all  conditions  of  their  eruption,  whether  regular  or 
irregular.  From  the  time  the  first  teeth  appear  until  the 
second  set  are  firmly  fixed  in  position,  the  alveolar  process 


38  IRREGULARITIES   OF  THE   TEETH. 

has  changed  throe  times;  consequently,  while  the  teeth  grow 
and  develop  independently  of  the  alveolar  process,  the  pro- 
cesses are,  to  a  certain  extent,  dependent  upon  the  teeth  for 
their  development,  po-ition  and  shape. 

Tin-  permanent  teeth,  taking  the  place  of  the  temporary 
teeth,  and  likely  to  be  dellected  in  any  direction  hy  the 
slightest  obstruction  or  want  of  space,  are,  indeed,  "  creatures 
of  circumstances." 

Mr.  Tomes  says:  "The  point  upon  which  it  is  impossible 
to  insist  too  strongly  is  this,  that  the  teeth,  when  they  are 
erupted,  do  not  come  down  and  take  their  places  in  a  bone 
already  prepared  for  them;  on  the  contrary,  that  which  is 
there  to  start  with  is  absorbed,  and  the  bone  in  which  they 
are  ultimately  implanted  is  built  up  around  them,  no  matter 
what  position  they  assume  subsequent  to  their  eruption." 
The  size  of  the  jaw  does  not  indicate  the  size  of  the  alveolar 
process.  The  teeth  may  erupt  toward  the  inner  border  of 
the  jaw,  when  the  process  will  naturally  build  up  about 
them,  and  will  be  smaller  than  the  jaw;  wrhile,  on  the  other 
hand,  the  teeth  may  be  directed  outward,  and,  as  a  result. 
the  process  will  be  larger  than  the  jaw. 

In  whatever  position  the  teeth  make  their  appearance 
in  the  jaw,  the  cheeks  and  lips  add  materially  in  directing 
their  position  externally,  and  the  tongue  internally.  The 
order  in  which  they  are  erupted  may  have  as  much  to  d<» 
with  the  causation  of  irregularities  as  any  one  thing.  This 
is  particularly  noticeable  when  the  bicuspids  and  lateral 
incisors  come  down  in  close  proximity,  and  the  cuspids  are 
left  outside  the  arch,  or  when  the  centrals,  the  laterals  and 
cuspids  are  in  place,  and  some  of  the  bicuspids,  which  have 
been  retarded  in  their  eruption,  are  forced  abnormally  inward. 
Lateral  incisors  and  wisdom  teeth  are  rather  frequently  out  of 
position,  since  their  tardy  development  allows  the  other 
teeth  t -cupy  the  space. 

It  will  be  observed  that  the  crowns  of  the  permanent 
centrals,  on  the  lower  jaw,  are  situated  below  and  posterior 
to  the  roots  of  the  temporary  teeth.  The  permanent  crowns. 


PAET   I — ANATOMY. 


39 


being  larger  and  requiring  more  space,  naturally  crowd  out- 
ward and  conflict  with  the  roots  of  the  temporary  teeth, 
thus  producing  absorption  of  the  entire  root.  The  roots  of 
the  temporary  teeth  may  be  all  removed  by  nature  in  this 
same  way.  If  the  crowrns  of  the  permanent  teeth  do  not 
come  in  contact  with  the  roots  of  the  temporary  teeth,  or 
if  from  any  cause  the  pulps  of  the  deciduous  teeth  are 
destroyed,  absorption  does  not  occur  to  any  extent,  and  the 
roots  are  not  removed.  The  permanent  teeth  are  then 


FIG.  19. 


deflected  either  into  the  mouth  or  out  toward  the  labial  or 
buccal  surfaces,  or  they  remain  imbedded  in  the  jaws. 

AVhen  temporary  teeth  are  extracted  on  account  of  decay, 
or  to  make  room  for  the  permanent  teeth,  the  cavity  occa- 
sioned by  such  extraction  fills  up  with  osseous  matter,  which 
deflects  the  permanent  teeth  outward  or  inward,  since  the 
tooth  cannot  penetrate  it.  Fig.  19  illustrates  a  case  of  this 
kind ;  a  represents  the  site  of  the  extracted  deciduous  tooth 
filled  with  cicatricial  tissue ;  b,  the  permanent  canine,  which 
has  been  deflected  outward. 


«  IIAPTER    IV. 

At  QUIRED  IKKi:«.l  I.AKITIKS. 

I'M  ler  tin-  general  head  of  etiology  of  acquired  irregular- 
ities may  In-  mentioned  tliuml),  lip,  ringer  and  longm- 
sucking,  and  long-continued  nipple  and  sugar-teat  sucking. 
Sonic  common  forms  of  irregularities  are  a-crihed  by  dill'er- 
cnt  writers  tn  thumb-sucking,  which,  in  the  author's  opinion. 
cannot  be  classed  under  that  head  of  causes.  Ind.-.-d.  \\. 
think  that  irregularities  in  the  permanent  teeth  arc  very 
rarely  the  result  of  thumb-sucking.  It  is  a  habit  acquired 
in  infancy  and  continued  while  the  first  teeth  are  in  the  jaw. 
when  the  roots  are  small  and  short  and  very  impressible. 
The  upper  teeth  are  easily  pushed  out  and  the  lower  pre<-ed 
in  bv  anv  constant  force.  Thumb-sucking  tends  to  enlarge 
the  arch,  and,  by  throwing  out  the  surfaces  of  the  upper  teeth . 
will  make  spaces  between  them,  at  the  same  time  making 
proper  occlusion  of  the  teeth  an  impossibility.  Fig.  20  i- 
taken  from  the  collection  of  Dr.  E.  D.  Swain,  of  Chicago. 

If  the  habit  be  not  overcome  when  the  second  -et  appear-, 
the  superior  incisors  will  be  pushed  out,  making  a  tan- 
shaped  arch,  and  the  pressure  of  the  object  will  produce 
absorption  of  the  processes,  or  the  alveolar  process  will 
assume  the  shape  of  the  object  sucked. 

In  the  lower  jaw  the  irregularities  are  reversed:  while  t  In- 
upper  teeth  are  thrown  out,  elongated  and  spread  apart,  the 
lower  incisors  are  forced  inward,  shortened  and  crowded 
together.  Pressure  upon  the  lower  jaw  in  thumb-sucking 
has  a  tendency  to  shorten  the  angle  of  the  jaw:  absorption 
and  deposition  of  the  bone  take  place,  so  that  the  lower  teeth 
articulate  one  tooth  back  of  the  normal  position. 

Dr.  Ballard,  of  London,  observed  that  the  prominence  of 
the  central  incisors  and  the  vaulted  arch  was  common  with 
idiots,  and  concluded  that  thumb-sucking  was  the  cause  of 
this  prominence,  and,  consequently,  of  the  idiocy.  While  it 

40 


PART    I — ANATOMY. 


41 


is  a  fact  that  this  peculiar  deformit}'  is  more  frequently 
found  among  a  given  number  of  idiots  than  in  the  same 
number  of  healthy  persons,  it  cannot  be  a  result  of  thumb- 
sucking,  for  the  following  reasons :  First,  if  the  irregularity 
were  produced  by  thumb-sucking,  the  deformity  would  exist 
on  one  side  of  the  median  line,  according  to  the  hand  which 
was  used,  rather  than  at  the  median  line,  where  most  of  these 
irregularities  are  located  ;  secondly,  the  vaulted  arch  could 
not  be  produced  by  thumb-sucking,  as  the  thumb  could  not 
reach  the  roof  of  the  mouth  to  produce  sufficient  pressure 
to  affect  the  arch.  The  vaulted  arch  and  the  V-shaped 


FIG.  20. 


jaw  are  not  always  associated,  the  V-shaped  jaw  being  as 
frequently  unaccompanied  by  the  vaulted  arch  as  it  is  found 
with  it. 

It  is  agreed  that  the  thumb-sucking  during  first  dentition 
changes  permanently  the  shape  of  the  jaws ;  but  before  the 
maxillary  bones  could  be  affected  the  teeth  would  be  thrown 
out  of  position,  and,  as  has  been  remarked  before,  irregular- 
ities of  the  first  set  of  teeth  are  seldom  seen.  Sucking  of  the 
tongue  and  sugar-teats  is  more  likely  to  produce  deformities 
of  the  bicuspids,  molars  and  hard  palate  than  of  the  anterior 
4 


42  IRREGULARITIES   OF   THE   TEETH. 

teeth,  mving  t«>  the  position  of  the  tongue.     Deformities  occur 
at  tlir  point  where  the  pressure  is  the  greatest. 

THE  CENTRAL  INCISORS. 

The  central  incisors  are  usually  regular  in  their  position, 
owing  to  the  manner  in  which  they  are  erupted.  They 
seldom  meet  with  resistance  in  their  transit.  a>  they  come 
<lown  into  place  outside  of  the  temporary  teeth.  The  lips 
a-sist  in  bringing  them  into  position.  Occasionally  the 
centraN  have  quite  a  space  between  them,  or  are  more  or 


Fie.  21. 


less  twisted,  the  mesial  surfaces  directed  outward  toward  the 
lip  or  inward  toward  the  palatine  surfaces.  These  condit i<  ms 
may  be  due  to  the  retention  of  the  deciduous  incisors  or 
their  roots;  to  the  resisting  properties  of  a  firm  suture  which 
unites  the  two  maxillary  bones;  to  the  early  eruption  of  the 
permanent  lateral  incisors;  to  arrested  development  of  the 
maxillary  bones;  to  the  presence  of  supernumerary  teeth, 
which  make  their  appearance  sometimes  1..  tween  the  een- 
trals  and  at  almost  any  position  on  the  palatine  Mirtaces; 
and  also  to  the  uncertain  progress  of  the  cuspids. 

•Jl   illustrates  the  upper  jaw  of  a  boy  twelve  years  of 


PART   I — ANATOMY.  43 

age ;  it  shows  the  right  side  of  the  jaw  in  a  normal  condition. 
The  cuspid  upon  the  left  side,  being  large  in  proportion  to 
the  other  teeth,  has  encroached  upon  the  lateral,  forcing  it 
into  the  palatine  region,  carrying  the  distal  surface  of  the 
central  around  so  that  the  palatine  surface  is  presented  to 
the  mesial  surface  of  the  right  central  incisor.  The  root  of 
the  central  incisor  being  round  and  conical,  it  is  easily 
rotated  in  its  socket  upon  coming  in  contact  with  another 
tooth  as  it  emerges  from  the  jaw.  The  incisors  sometimes 
lap,  this  being  due  either  to  a  contracted  jaw  or  to  the 
lateral  pressure  of  the  adjoining  teeth. 

THE  LATERAL  INCISORS. 

The  lateral  incisors  of  both  jaws  frequently  erupt  in  an 
abnormal  position.  Owing  to  the  inferior  size  of  their 
crowns  and  roots,  they  are  easily  influenced  out  of  position 
by  their  contact  with  the  centrals  or  cuspids.  The  usual 
deflection  of  these  teeth  is  directly  posterior  to  the  normal 
position,  and  slightly  or  wholly  behind  the  centrals.  Their 
crowns  may  stand  with  their  labial  surfaces  parallel  with 
the  centrals,  or  they  may  rotate  to  any  angle.  Their  abnor- 
mal position  may  be  caused  by  retention  of  the  temporary 
teeth  of  their  roots,  by  inharmonious  growth  of  the  alveolar 
process  and  teeth,  or  by  contact  of  the  crowns  of  the  cuspids, 
bicuspids  and  molars.  It  is  possible  for  them  to  project 
toward  the  labial  surface  of  the  alveolar  process  from 
similar  causes. 

»THE  CUSPID  TEETH. 
These  teeth  very  commonly  take  an  abnormal  position  in 
the  jaw,  from  several  causes.  The  follicles  have  a  peculiar 
relation  to  the  other  follicles  in  the  jaw ;  this,  together  with 
the  extreme  length  of  root  and  the  time  of  their  eruption, 
makes  an  irregular  appearance  almost  a  certainty.  The  inci- 
sors, with  their  long  roots  anteriorly  and  the  bicuspids  and 
molars  posteriorly,  afford  strong  barriers  to  obstruct  the 
regular  progress  of  the  cuspids.  If  the  temporary  teeth  are 


44 


IRREGULARITIES   OF   THE  TEETH. 


Fio.  22. 


allowed  to  n-inain  until  the  permanent  cuspids  are  ready  to 
appear,  tin-  latter  will,  in  a  majority  of  cases,  be  pushed  into 
their  proper  places  by  the  lips  and  cheeks,  which  press  the 
cu-pid-  toward  the  median  line,  and  thus  force  the  process 
containing:  the  incisor  teeth  forward.  If  the  bicuspids  have 
worked  their  way  forward,  so  that  tin-re  is  nut  space  enough 
lor  the  remaining  teeth,  the  canines  will  encroach  upon  the 
laterals,  and  either  forca  them  out  of  place  or  rotate  them  in 
their  soekeN.  These  teeth  are  inclined  to  move  toward  the 
median  line,  and  take  any  position  anterior  to  the  bicuspids. 
Fig.  2'J  illustrates  a  model  presented  to  me  by  Dr.  I.  I  >. 

Shepard,  of  Boston.  The 
right  cuspid  appears 
through  the  gum  l.e- 
tween  the  central  and 
lateral  incisors,  while 
upon  the  left  side  a  su- 
pernumerary  tooth 
stands  between  the  cen- 
tral and  laternl.  and  the 
left  cuspid  is  erupting 
between  the  lel't  central 
and  the  supernumerary 
tooth.  The  pro- lire  of 
the  cuspids  i-  -o  M-]v;it  in 
the  jaws  as  to  demoral- 
ize all  theanterior  teeth. 
Fig.  23  illustrates  tin- 
model,  pre-elited  to  Hie 
by  Dr.  John  S.Marshall. 
of  Chicago,  of  the  lower 

jaw  of  a  woman  thirty-seven  years  of  age.  It  shows  the 
right  permanent  cuspid  situated  between  the  central  incisors. 
This  tooth  made  its  appearance  when  the  patient  was  thirty- 
two  years  of  age.  The  right  temporary  cuspid  is  still  in 
place. 

\\  hen  th<-  crown  of  the  cuspid  is  on  the  palatine  surface 


PART   I — ANATOMY. 


45 


FIG.  21. 


of  the  roots  of  the  laterals  and  bicuspids  (especially  if  the 
temporary  canine  remain  in  the  jaw),  it  will  deflect  into  the 
roof  of  the  mouth.     Fig.  24  illustrates  such  a  case.     When 
the   cuspids    begin    to 
erupt    they    sometimes 
strike   the  roots  of  the 
lateral  incisors,  or   the 
first  bicuspids,  or  both, 
and  are  rotated  in  their 
sockets  on  the  principle 
of  the   inclined   plane. 
The  molars  and  bicus- 
pids may  work  forward 
and   fill   all  the  space, 
either  because  the  tem- 
porary   cuspids    have' 
been  extracted  too  early 
or  retained  too  long,  and 
the  permanent  cuspids 
remain  imbedded  in  the  jaw. 

Irregularities  in  the  arrangement  of  the  bicuspids  and 
molars  are  treated  under  the  heads  of  irregularities  caused 
by  protracted  retention  and  too  early  extraction  of  the  tem- 
porary teeth.  The  causes  already  enumerated  which  pro- 
duce irregularities  of  the  teeth  of  the  upper  jaw  are  also 
responsible  for  the  irregularities  of  the  teeth  of  the  lower  jaw. 
Added  to  these  causes  is  the  contact  of  the  inferior  with  the 
superior  teeth.  Frequently  the  cutting  edges  of  the  lower  teeth, 
in  their  development,  come  in  contact  with  the  contracted 
arch  of  the  upper  jaw,  and  are  turned  from  their  regular 
course.  These  irregularities  are  difficult  to  correct. 

HEREDITY  IN  ITS  RELATIONS  TO  IRREGULARITIES. 

It  is  a  fact  universally  recognized  that  various  morbid 
conditions  and  peculiarities  of  structure  are  often  transmitted 
from  parent  to  child,  through  many  generations.  This  law 
of  heredity  is  almost  universal  in  its  application,  and  its 


46  IRREGULARITIES   OF  THE   TEETH. 

influencr  1'iay  be  either  enhanced  or  depreciated  through 
Micces-ive  or  alternate  generations,  until  we  have,  upon  the 
our  han.l,  a  total  disappearance  of  the  hereditary  impression, 
or,  upon  the  other,  an  increase  so  great  that  the  condition 
become  incompatible  with  the  life  of  the  individual.  This 
variation  i.<  a  fortunate  circumstance,  as  by  it  the  human 
raer  i-  protected  from  certain  destruction. 

This  plan  of  variation  is  powerful  for  good  or  evil,  accord- 
ing to  the  environment  of  the  individual,  or  of  the  family  to 
which  lit-  belongs.  This  fundamental  evolutionary  law  of 
heredity  is  nowhere  more  manifest  than  in  the  case  of  per- 
versions of  development  of  both  internal  and  external  organs, 
cither  embryonal  or  post-natal,  and  it  is  a  mdst  powerful 
factor  in  the  production  of  deformities  of  the  jaw  and  irregu- 
larities of  the  teeth.  Not  only  does  this  hold  true  in  the  e 
of  general  irregularities  due  to  maxillary  deformities,  but  it 
also  applies  to  malformations  of  individual  teeth.  Thus,  the 
author  has  observed  in  a  family  consisting  of  mother,  daugh- 
ter and  granddaughter,  a  peculiar  fissured  condition  of  the 
enamel  upon  the  labial  surface  of  a  left  superior  lateral 
incisor. 

It  is  not  uncommon  for  a  child  to  possess  peculiarities  of 
the  teeth  of  one  jaw  resembling  those  present  in  the  father, 
while  the  other  presents  irregularities  of  development  pre- 
cisely identical  with  those  present  in  the  mother  :  a  gain,  one 
parent  may  transmit  peculiarities  of  maxillary  development 
while  tin- other  transmits  certain  characteristic  appeara: 
of  the  teeth.  Much  has  been  said  of  late  regarding  the  influ- 
ence of  ante-natal  impressions  upon  the  development  of 
deformities,  and  if  the  claims  advanced  be  but  half  true,  it 
is  probable  that  the  teeth  and  jaws  may  occasionally  sutler 
their  share  of  the  resulting  detriment.  Evidence  of  dental 
deformities  from  this  cause  is,  of  necessity,  difficult  to  obtain. 
A  case  is  recalled,  however,  in  which  a  peculiar  condition  of 
irregularity  of  the  teeth  was  attributed  by  the  mother  to  h'-r 
constant  worry,  during  gestation,  lest  the  coming  child  should 
have  teeth  as  irregular  as  her  own.  When  dentition  was 


PART    I — ANATOMY. 


47 


finally  completed  in  the  child,  the  arrangement  of  the  teeth 
was  identical  with  those  of  the  mother.  This  case  is  not  by 
any  means  advanced  as  a  positive  evidence  of  ante-natal 
impressions,  but  b3cause  of  its  suggestiveness. 

Notwithstanding  what  has  been  said  regarding  the  influ- 
ence of  heredity,  it  must  be  confessed  that  we  are  often  abso- 
lutely unable  to  determine  the  precise  degree  of  influence 
exerted  by  it,  even  when  we  are  convinced  that  it  is  a  pow- 
erful factor.  It  is  evident  to  any  one,  upon  reflection,  that 
the  causes  which  will  produce  deformities  independent  of 
hereditary  influences  will  also  prevent  the  latter  from  acting 
as  they  otherwise  would. 

As  has  been  remarked  elsewhere,  the  teeth  are  creatures  of 
circumstances,  i.  e.,  they  are  developed  independently  of  the 
alveolar  process,  hence  their  order  of  development  and  the 
resistance  imparted  by  other  teeth  and  roots  all  combine  to  pro- 
duce irregularities ;  in  short,  local  causes  produce  a  majority 
of  irregularities,  and  modify  formations  which  might  other- 
wise be  the  exact  counterpart  of  those  presented  by  the  teeth 
of  the  parent. 

The  following  cases  in  practice  illustrate  this  theory.  In 
one  family  under  my  observation  the  father's  jaws  are  well 
developed,  and  con- 
tain large,  strong 
teeth.  The  mother's 
jaws  are  small,  the 
teeth  being  regular 
in  the  lower  max- 
illa. In  the  upper 
maxilla  the  central 
incisors  are  regular 
and  in  normal  posi- 
tion, but  the  cuspids, 
bicuspids  and  mo- 
lars have  come  for- 
ward and  filled  the 
spaces  occupied  by  the  laterals,  which  were  extracted  at  the 


FIG.  2o. 


FKI.  2fl. 


4g  IRREGULARITIES  OF  THE  TEETH. 

aee  of  thirteen.     Two  sons  (their  only  children)  have  lower 
jaws  and  teeth  closely  resembling  the  mother's.     The  upper 
jaws  and    teeth  of  both  resemble  the  father's  in  size  and 
Strength,  but,  unlike  the  father's,  they  are  very  irregular 
in  position     These  irregularities  are  not  due   to 
roaoe  in  the  jaws,  which  are  sufficiently  large  to  admit 
teeth  with  regularity.    This  tendency  to  irregularity  of  posi- 
tion  i<  apparently  a  marked  inheritance  from  the  mother. 
Fig  25  is  tin-  model  of  the  jaws  of  the  elder  son,  who  is  four- 
teen years  of  age;  as  may  be  observed,  the  central  incisors  .,t 
the  upper  jaws  are  regular,  the  laterals  are  forced  l.y  the  cus- 
pids some  distance  inside  the  natural  line;  the  cuspids, bicui- 

pids  and  molars  are 
anterior  to  their  nor- 
mal position.  Fii:. 
26  illustrates  the 
jaws  of  the  younger 
son,  aged  eleven.  Tin- 
centrals  and  laterals 
erupted  at  the  pn.per 
time.  The  cuspids 
are  encroaching  upon 
them  to  such  an  ex- 
tent as  will  eventu- 
ally form  a  Y-shaped 
arch.  Both  boys  have  been  under  my  care  from  the  begin- 
ning, the  temporary  teeth  being  removed  at  the  proper 

time. 

It  will  be  observed  that  the  tendency  toward  irregularity 
in  arrangement  is  decidedly  inherited  from  the  mother. 
The  renditions  are  so  modified  by  local  influences  that 
although  the  hereditarily  irregular  arrangement  comes  in  mi 
the  mother,  the  teeth  are  not  exact  counterparts  of  the 
mother's  irregularity,  nor  are  they  alike.  It  is  questionable 
whether  exact  counterparts  of  irregularities  are  ever  inher- 
ited from  parents.  Various  local  interferences  and  condi- 
tions will,  as  we  have  seen,  influence  this  one  way  or  the 


PART  I — ANATOMY.  49 

other.  Transmissions  of  small  jaws  and  of  peculiarities  of 
individual  teeth  are,  however,  common. 

In  1864,  Messrs.  Cartwright  and  Coleman,*  of  London, 
examined  some  200  skulls  in  the  crypt  of  Kythe  Church, 
Kent,  which  had  been  deposited  there  for  centuries.  They 
found  the  alveolar  processes  and  teeth  perfectly  developed 
and  formed. 

In  1869,  Mr.  John  R.  Mummery,  of  London,  read  a  paper 
before  the  Odontological  Society  of  Great  Britain,  in  which 
he  gave  a  report  of  his  extended  researches,  including  over 
3000  skulls  of  ancient  and  modern  uncivilized  races,  and 
concluded  that  the  early  and  half-savage  people  were  freer 
from  dental  irregularities  than  moderns.  Dr.  Xichols,  of 
New  York,  has  examined  the  mouths  of  thousands  of  In- 
dians and  Chinese,  and  says  that,  with  but  one  exception,  he 
never  found  an  instance  of  irregularities  in  either  of  these 
races. 

1  can  confirm  the  statement  of  Dr.  Nichols  as  regards  the 
Chinese,  having  examined  the  teeth  of  many  of  them  on 
the  Pacific  coast.  The  above  reports,  together  with  the 
testimony  of  other  investigators,  show  that  ancient  uncivil- 
ized and  nomadic  barbarians  have  perfectly-shaped  dental 
arches. 

The  interesting  circumstance  that  irregularities  occur  more 
frequently  now  than  formerly,  and  among  people  living  in 
new  countries,  would  suggest  the  idea  that  irregularities 
caused  by  heredity  may  result  from  the  intermarriage  of 
different  nationalities,  the  offspring  of  such  unions  partak- 
ing irregularly  and  in  different  degrees  of  the  racial  pecu- 
liarities of  maxillary  development  of  either  or  both  parents, 
[t  is  probable  that  the  varying  character  of  the  food,  and 
the  abuse  of  the  teeth  incident  to  the  depraved  hygiene  of 
lodern  civilization,  have  much  to  do  with  dental  malforma- 
ions.  Again,  the  higher  the  evolutionary  type  of  indi- 
viduals, the  more  imperfect  the  teeth  and  jaws  become. 


Kingsley's  "Oral  Deformities." 


50  IRREGULARITIES   OF   THE   TEETH. 

The  nearer  the  monkey,  and  the  farther  removed  from 
refined  and  civili/ed  man,  the  better  the  teeth.  As  the 
animal  becomes  less  and  less  dependent  upon  his  jaw- and 
teeth  fnr  a  livelihood,  the  less  perfect  these  strut-tun -s 
become,  and  after  the  lapse  of  many  generations  marked 
variations  and  imperfections  of  development  are  logically 

t«>  lie  expected. 

Iii  conclusion,  it  may  be  said  that  in  our  studies  of  dental 
and  maxillary  irregularities.  \ve  must  not  only  take  into 
consideration  the  transmission  of  individual  peculiarities, 
hut  the  all-pervading  and  general  evolutionary  law  of 
In  rulity. 

ARRESTED  MAXILLARY  DEVELOPMENT  AS  A  CAUSE  OF 

IKKKtilLAKITIES. 

The  superior  and  inferior  maxilla3  are  developed  from 
separate  and  distinct  ossific  centres,  those  of  the  inferior 
U-ing  the  tirst  of  the  bones  of  the  skeleton  to  exhibit  signs 
of  ossification;  not  only  do  the  maxilla?  develop  independ- 
ently of  each  other,  but  each  bone  is  practically  developed 
in  two  lateral  halves,  which  subsequently  unite  by  fusion. 
the  line  of  fusion  becoming  finally  more  or  less  obliterated. 
The  teeth,  already  laid  down  at  birth,  develop  and  grow 
independently  of  the  maxilla3  and  alveolar  processes. 

Under  such  circumstances  of  development  and  growth  it 
is  obvious  that  perfect  harmony  must  exist,  else  deformity 
is  sure  to  ensue,  e.  g.,  the  separate  halves  of  the  maxilla- 
must  have  a  corresponding  degree  and  mode  of  develop- 
ment, else  irregularity  is  inevitable.  In  the  same  way.  a 
difference  in  the  form  of  the  upper  and  lower  jaws  may 
atlect  the  regularity  of  the  teeth. 

A  lack  of  correspondence  between  alveolus  and  jaw.  or 
jaw  and  teeth,  is  almost  certain  to  cause  serious  deformity. 
The  greater  deformities  due  to  inharmonious  development, 
such  as  cleft  palate,  harelip,  underhung  jaw  and  protruding 
upper  jaw,  are  sufficiently  familiar,  but  their  relation  to 
irregularities  is  not  generally  appreciated.  Violate  the  general 


PART   I — ANATOMY.  51 

developmental  law  of  harmony,  and  we  may  have  deformi- 
ties which,  although  varying  in  degree,  are  precisely  iden- 
tical in  kind.  When  the  fact  that  the  foetus  is  practically 
developed  in  two  lateral  segments  is  taken  into  considera- 
tion, all  deformities  which  exist,  or  a  predisposition  to 
which  exists,  at  birth  become  easily  understood. 

There  is  a  marked  difference  between  the  superior  and 
inferior  maxilla  in  respect  to  congenital  and  acquired 
deformities.  The  superior  maxilla  is  exposed  to  pressure 
and  many  extraneous  influences  due  to  the  arrangement  of 
the  various  bones  with  wljich  it  articulates — there  being 
eight  of  these  articulations.  The  lower  maxilla  is  developed 
free  and  independent  of  the  other  bones  of  the  face,  and,  as 
a  consequence,  is  in  nowise  affected  by  any  lack  of  harmony 
which  may  exist  between  them.  Thus,  the  fact  of  the 
relative  infrequency  of  deformity  or  imperfect  development 
of  the  inferior  maxilla,  as  compared  with  the  superior,  is 
readily  explained.  There  is  another  plausible  explanation 
for  this  difference :  The  upper  jaw,  being  fixed,  is  not  actively 
exercised,  and,  consequently,  has  no  special  stimulus  to 
development ;  the  lower  jaw,  on  the  other  hand,  is  mobile, 
and  acted  upon  by  powerful  muscles  in  such  a  manner  that 
an  active  blood  supply  becomes  necessary.  With  this 
increased  blood  supply  comes  increased  growth  and  nutrition. 
There  is  this  to  be  said,  however,  in  relation  to  this  subject, 
etc.,  viz. :  that  the  lower  jaw  is  more  likely  than  the  upper  to 
present  family  characteristics  of  configuration  not  within  the 
range  of  actual  deformities. 

From  what  has  been  said,  it  is  obvious  that  the  considera- 
tion of  deformities  due  to  arrested  development  must  neces- 
sarily be  limited  to  the  upper  jaw.  These  deformities 
merit  special  attention.  There  are  two  principal  deformities 
dependent  upon  mal-development  of  the  superior  maxilla, 
viz.:  The  Y-shaped  arch  and  the  saddle-shaped  arch.  The 
most  common  of  the  two  forms  is  the  V-shaped  arch  (Fig.  27). 
The  incisors  protrude  and  are  rotated  in  such  a  manner  that 
their  mesial  surfaces  present  anteriorly,  forming  the  point 


52  IRREGULARITIES  OF  THE   TEETH. 

of  the  V,  the  bicuspid  region  is  contracted,  and  the  roof  of 
the  mouth  may  or  may  not  be  vaulted;  the  cuspids  are 
sometimes  in  the  line  of  the  other  teeth,  and  sometimes 
entirely  outside  the  arch  ;  we  occasionally  find  in  these  cases 
tin-  l<»wrr  incisors  crowded,  but  the  bicuspids  and  molars  an- 
nearly  always  in  their  proper  places.  Many  theori.-s  aiv 
advanced  in  explanation  of  this  deformity.  Mr.  Charles 
Tomes  says  that  "this  malformation  is  associated  with 
grratly-i'iilartrt-'d  tonsils,  which  necessitates  breathing  bein.ir 
carried  on  with  the  mouth  open.  Now,  as  every  one-  can 


Fio.  27. 


easily  verify  for  himself,  the  effect  of  the  mouth  Lcin-  In  1.1 
open  is  to  increase  the  tension  of  the  soft  parts  almut  its 
angles,  and  the  result  of  the  increased  pressure  i<  to  bring 
about  a  bending  inward  at  the  corresponding  point.  /.  • .. 
the  bicuspid  region;  at  the  same  time  the  median  portion 
of  the  arch  escapes  the  controlling  pressure  which  would 
have  been  exercised  by  closed  lips,  and  the  effect  of  tli; 
traceable  in  the  excessive  prominence  of  the  median  pair  of 
incisors,  and  also  in  their  oblique  position,  which  makes 


PART    I — ANATOMY.  53 

them  correspond  with  the  form  assumed  by  the  inner  surface 
of  the  lips  when  the  mouth  is  open." 

Dr.  Norman  W.  Kingsley  says :  "  The  pinched  or  V-shaped 
dental  arch  I  believe  to  be  nearly  always  of  congenital 
origin — that  is,  an  inherited  tendency,  favored,  in  all  proba- 
bility, by  like  circumstances  with  those  which  initiated  it 
in  the  ancestry — while  the  broad  or  rounded  form  is  often, 
if  not  always,  due  to  mechanical  causes." 

Mr.  Oakley  Coles  says:  "After  carefully  examining  the 
works  of  the  various  writers  on  the  subject  of  microcephalic 
idiocy,  there  seems  sufficient  evidence  to  justify  the  belief 
that  premature  ossification  of  the  sutures  is  the  rule  in  the 
majority  of  these  cases,  and  we  may  therefore  assume,  if 
we  cannot  absolutely  conclude,  that  this  influence  operates 
powerfully  in  the  production  of  the  dental  deformity  known 
as  the  lambdoid  jaw  or  VTshaped  arch." 

Mr.  Cartwright  says:  "Want  of  space  in  the  bones  of  the 
jaws  may  be  defined  as  the  true  cause  of  irregularity  in  the 
position  of  the  teeth  in  the  majority  of  instances,"  and  then 
suggests,  that  "  this  abnormal  condition  may  be  the  result 
o/  high  breeding."  It  will  be  observed  that  the  V-shaped 
arch  is  nearly  always  associated  with  the  superior  maxilla 
and  with  the  permanent  teeth. 

In  the  opinion  of  the  author,  the  deformity  above  described 
cannot  be  due  to  thumb-sucking.  In  the  first  place,  the 
teeth  chiefly  concerned  in  the  deformity — viz. :  the  central 
and  lateral  incisors  and  the  first  permanent  molars — are  all 
in  position,  as  a  rule,  from  the  sixth  to  the  eighth  year,  and, 
when  erupted,  usually  present  a  normal  form  and  position 
in  their  alveoli ;  any  changes  from  the  normal,  therefore,  will 
be  observed,  in  these  cases  of  V-shaped  deformity,  to  occur 
after  their  eruption.  Now,  the  habit  of  thumb-sucking 
antedates  the  eruption  of  these  teeth  by  a  considerable  time, 
and  the  child  is  usually  broken  of  its  habit  long  prior  to 
their  eruption.  It  is  difficult,  upon  this  ground  alone,  to 
appreciate  the  alleged  correlation  of  the  pernicious  habit 
of  thumb-sucking  with  the  V-shaped  arch.  Again,  this 


54  IRREGULARITIES  OF  THE  TEETH. 

deformity  always  terminates  at  the  median  line  in  an  acute 
aii-1'-.  while  in  the  thumb-sucker  both  the  temporary  and 
permanent  incisors  are 'rounded  out.  Another  ini|M.rtant 
n.u>id«  ration  is  the  fact,  that,  if  due  to  thumb-sucking,  the 
deformity  would  \>e  most  likely  to  be  upon  one  or  tin-  other 
side  of  the  median  line,  according  to  the  position  of  the 
force,  instead  of  at  the  median  line.  The  spaces  ••\isting 
between  the  teeth  of  the  thumb-sucking  child  are  never  seen 
in  the  V-shaped  arch. 

It  is  noteworthy,  also,  that  the  thumb  cannot  well  be  car- 
ried   into  the  mouth  so  far  as  would  be  necessary  to  the 


Fio. 


formation  of  the  V-shaped  arch ;  and  even  were  it  possible, 
the  resulting  deformity  would  be  an  arc  of  a  circle  rather 
than  an  angular  V.  Fig.  28  shows  a  perfectly  Hat  arch, 
the  anterior  teeth  rounded  out,  with  space  between  them. 
This  is  a  marked  case  of  thumb-sucking  in  a  child  al><>ut 
fourteen  years  of  age.  Dr.  Kingsley  is  probably  correct  in  so  tar 
as  the  relation  of  heredity  to  the  small,  undeveloped  maxilla 
is  concerned,  but  that  the  V-shaped  arch  is  due  to  heredity 
per  se  is  questionable.  When  it  does  occur,  it  is  by  acquire- 
ment from  causes  acting  locally  upon  an  hereditarily  small 
maxilla.  At  the  beginning  of  the  V-shaped  arch  we  find 


PART   I — ANATOMY.  55 

the  following  conditions :  The  first  permanent  molars  are 
firmly  fixed  in  the  jaw,  owing  to  their  size  and  long  roots, 
the  centrals  and  laterals  have  erupted,  both  bicuspids  are 
descending  into  place  against  the  firm  first  molars.  Owing 
to  the  lack  of  space  which  obviously  exists  in  the  imper- 
fectly-developed maxilla,  with  which  the  V-shaped  arch  is 
always  associated,  these  teeth  cause  the  alveolar  process  to 
be  carried  forward  by  absorption  and  deposition  of  bone. 
This  forward  movement  takes  place  at  the  point  of  union  of 
the  inter-maxillary  and  superior  maxillary  bones. 

The  roots  of  the  six  anterior  teeth,  being  conical  in  shape, 


FIG.  29. 


press  forward  and  inward  in  a  rotary  manner,  the  cuspids 
against  the  laterals,  the  laterals  against  the  centrals,  and, 
assisted  by  the  pressure  from  the  muscles  of  the  cheeks  and 
lips,  produce  an  arch,  which  takes  the  V  shape.  Fig.  29 
shows  the  model  of  the  jaw  of  a  boy  fourteen  years  old,  demon- 
strating the  cause  of  the  V-shaped  arch.  The  right  side 
is  normal,  excepting  the  lateral  incisor,  which  is  slightly 
rotated  in  its  socket.  The  left  side  forms  half  of  a  perfect 
V-shaped  arch.  The  abnormal  position  is  owing  to  the  too 
early  extraction  of  the  temporary  cuspids,  thus  giving  space 


IRRFXJULARITIFJS   OF   THE   TEETH. 


for  the  fir>t  permanent  molars  and  bicuspids  to  work  for- 
ward. They  iilled  one-fourth  of  an  inch  of  the  spare  made 
vacant  by  the  loss  of  the  temporary  cuspids,  and  forced  the 
permanent  cuspid,  when  erupted,  forward.  The  pressure  of 
the  cuspid  root,  ami  of  the  lip  and  cheek,  have  carried  the 
lateral  inci-or  into  the  palate  and  rotated  the  centrals 
around.  Had  the  sain ••  conditions  existed  on  the  right  side, 
the  V-shaped  arch  would  have  been  complete.  The  cuspids 
may  l»e  located  in  a  direct  line  with  the  other  teeth,  or. 
from  want  of  room,  may  be  situated  entirely  outside  the 
arch.  The  died  of  pressure  of  the  cuspids  npi.n  the  alveolar 
process  in  cither  case  is  precisely  the  same. 

THE  SADDLE-vSHAPED  JAW. 

Another  deformity  of  the  jaw   and    teeth    which    is   also 
attributed  to  thumb-sucking  is  illustrated  in    Fig.  :!<).  and 

is  called  the  ".-addle- 
shaped  jaw."  The  ante- 
rior teeth  an-  usually  in 
a  normal  position.  They 
either  stand  straight 
from  the  alveolar  pro- 
'••  ss  or  the  cutting  ed 
project  slightly.  They 
are  seldom  irregular  in 
position,  l.eing  protected 
from  the  anterior  j  ress- 
ure  of  the  posterior  teeth 
by  the  cuspid  teeth. 
When,  as  is  occasionally 
the  case,  the  deformity 
exiflta  on  the  lower  jaw,  we  find  the  incisors  and  cuspids  in 
a  straight  line.  This  straight  appearance  of  the  anterior 
teeth  is  produced  by  the  anterior  pressure  of  the  hidi>pids 
and  molars  against  the  cuspids,  which  are  carried  forward 
on  a  line  with  the  incisors.  The  bicuspids  and  lirst  molar- 
are  situated  considerably  inside  of  the  arch— the  second 


PART   I — ANATOMY.  57 

and  third  molars  taking  an  oblique  direction  laterally,  with 
the  roof  of  the  mouth  vaulted.  Like  the  teeth  of  the  V- 
shaped  arch,  the  first  molars,  bicuspids,  cuspids,  and  some- 
times the  incisors,  are  wedged  close  together.  This  fact 
would  naturally  suggest  as  a  cause  the  want  of  develop- 
ment of  the  jaw. 

A  gentleman  under  my  care  is  possessed  of  fine  physique 
and  well-developed  frame,  but  has  peculiarly  small  jaws  and 
processes  compared  with  the  other  bones  of  the  body.  The 
teeth  of  the  upper  jaw  form  almost  a  V-shaped  arch,  those 
of  the  lower  jaw  the  saddle-shaped  arch.  Like  the  V-shaped 
arch,  the  saddle-shaped  arch  does  not  begin  to  form  until 
after  the  eruption  of  the  first  permanent  molars.  This 
deformity  has  its  primary  cause  in  the  location  of  the  crowns 
of  the  permanent  teeth  in  a  dwarfed  alveolar  process. 
Instead  of  the  bicuspids  and  molars  being  located  in  the 
jaws  in  their  normal  positions — illustrated  in  Fig.  31  by 
A-B — they  stand  on  a  line  rep- 
resented by  C-D.  This  abnor- 
mal  condition  in  the  jaw  may 
be  a  natural  position  of  the 
follicles,  or  the  bicuspids  may 
be  influenced  by  the  roots  of 
the  temporary  teeth  and  the 
crowns  directed  toward  the 
roof  of  the  mouth. 

On  the  eruption  of  the  per- 
manent  teeth,  the   order  is     X  C 
changed    considerably :    the 

centrals  and  laterals  come  into  position  in  their  natural 
order,  but  instead  of  the  bicuspids  making  their  appearance 
next,  the  cuspids  take  their  positions.  These  teeth  make  a 
fixed  point  of  resistance  in  the  anterior  part  of  the  mouth. 
The  first  permanent  molar,  which  is  already  in  position  with 
its  long  and  large  roots,  is  working  forward,  and  has  also 
become  a  fixed  point  in  the  posterior  part  of  the  mouth. 
The  space  between  the  first  molar  and  the  cuspid  is  smaller 
5 


-,s  IRREGULARITIES   OF   THE  TEETH. 

than  the  long  diameter  of  the  crowns  of  the  bicuspids,  and 
both  an-  crowded  in  toward  the  roof  of  the  mouth.  It 
sometime-,  happens  that  the  first  bicuspid  erupts  and  sect] 
it>  position  1  w fore  tlie  second  bicuspid  makes  its  appearance. 
In  this  case  the  crown  of  the  first  permanent  molar,  in  work- 
ing forward,  comes  in  contact  with  the  crown  of  the  sm.nd 
bicuspid  in  siu-h  a  manner  as  to  form  an  inclined  plane,  and 
in  this  way  the  second  bicuspid  is  carried  inside  the  arch 
and  is  often  turned  in  its  socket,  the  cusps  facing  the  ante- 
rior and  posterior  parts  of  the  mouth.  Nature  provides  sup- 
port lor  the  teeth  in  whatever  position  they  may  a— nine; 
the  alveolar  process  is  built  up  about  them,  giving  them 
strength  and  firmness. 

The  extreme  lateral  position  and  undeveloped  condition 
of  the  second  and  third  molars  and  the  alveolar  proce> 
caused  by  the  pressure  of  the  tongue.  The  arch.  l»ein^-  con- 
tracted to  such  an  extent  that  the  tongue,  in  the  act  of 
>\\  allowing,  is  forced  backward,  consequently  thickens  and 
spread-  out  and  produces  pressure  upon  the  posterior  part  of 
the  upper  and  lower  jaw.  The  same  condition  of  the  teeth 
i>  also  noticeable  in  the  jaws  when  the  arch  is  very  shallow, 
and  is  also  the  result  of  a  want  of  room.  It  is  a  mistaken 
idea  that  the  high  arch  is  always  associated  with  the  V- 
shaped.  the  saddle-shaped  arch,  or  the  arch  of  the  tlr'inb- 
sucker.  The  author  has  observed  many  such  cases,  and  has 
noticed  quite  as  many  with  shallow  as  with  high  arches. 

1 1. 'REGULARITIES  CAUSED  BY  THE  PROLONGED  RETKMIoN*  OF 
THE  TEMPORARY  TEETH. 

The  period  of  life  during  which  the  shedding  of  the  decid- 
uous teeth  and  the  eruption  of  the  permanent  set  occurs 
iiio-i  critical  one  in  the  formation  and  arrangement  of  the 
permanent  teeth.  The  first  small  teeth  are  being  supplanted 
by  large  ones,  and  at  the  same  time  the  jaw  is  changing.  The 
child  should  at  this  time  be  under  the  care  of  a  dentist  who 
has  the  ability  to  assist  nature  in  perfecting  the  change.  If 
the  process  be  left  entirely  to  nature,  complicated  deformities 


PART    I ANATOMY.  59 

may  arise,  which,  with  judicious  treatment,  might  have  been 
prevented. 

As  the  permanent  tooth  shows  signs  of  advancing,  the  tem- 
porary tooth  upon  which  it  impinges  should  be  examined, 
and  removed  if  loose  or  if  its  room  be  needed.  By  attention 
to  this  particular,  and  to  the  articulation  as  the  teeth  take 
their  places,  further  trouble  will  often  be  avoided. 

Much  depends  upon  the  location  of  the  follicle  of  the  per- 
manent tooth  in  the  alveolar  process  in  its  relation  to  the 
root  of  the  temporary  tooth.  These  follicles  are  not  always 
located  directly  at  the  apices  of  single  roots  or  between  the 
roots  of  the  molars,  it  being  common  to  find  them  some  dis- 
tance from  these  points.  When  this  is  the  case,  the  vascular 
papilla  (which  is  situated  directly  upon  the  crown  of  the 
advancing  permanent  tooth,  and  is  the  organ  which  nature 
provides  for  removing  the  roots  of  the  temporary  teeth)  does 
not  perform  its  function. 

The  permanent  tooth  will  remain  imbedded  in  the  jaw,  or 
will  deflect  to  one  side,  and  appear  either  outside  or  inside  of 
the  arch.  We  sometimes  find  the  permanent  tooth  forced 
against  a  single  root  or  between  the  roots  of  a  molar  and 
the  surrounding  healthy  tissue.  Again,  it  is  more  common 
than  otherwise  to  find  the  molars  decayed  and  pulps  exposed 
or  dead  ;  in  such  cases  the  roots  of  the  temporary  teeth  are 
never  absorbed,  and  the  permanent  teeth  are  either  retained 
until  these  teeth  are  removed  or  are  erupted  in  an  abnormal 
manner.  Et  is  a  common  occurrence  to  find  the  crowns  of 
the  permanent  teeth  deflected  and  making  their  appearance 
inside  or  outside  the  arch,  owing  to  the  long  slender  conical 
roots  of  the  temporary  incisors  and  the  position  of  the  dental 
follicle  of  the  permanent  incisors.  In  either  case  the  corre- 
sponding tooth  of  the  temporary  set  should  be  removed  and 
the  permanent  tooth  pressed  into  place  with  the  fingers. 
This  same  condition  of  the  incisors  is  liable  to  occur  in  the 
upper  jaw,  but  they  are  less  apt  to  appear  inside  of  the  arch 
than  in  the  lower  jaw.  AVheii  this  occurs,  the  temporary 
teeth  must  be  removed  and  the  permanent  centrals  be  pushed 


60  IRREGULARITIES   OF   THE   TEETH. 

out  with  the  finger  until  they  occlude  outside  of  the  inferior 
incisors. 

When  they  appear  outside  of  the  arch,  and  the  temporary 
incisors  an-  « -xtruc -t«-d.  the  pressure  of  the  lips  will  usually 
bring  them  into  line.  The  same  conditions  occur  in  regard 
to  the  lateral  incisors,  and  the  same  treatment  should  be 
•dopted. 

It  is  very  important  to  retain  the  temporary  cuspid  until 
the  eruption  of  the  permanent  tooth.  When  this  time  lias 
arrived,  the  temporary  tooth  should  be  removed  to  allow  the 
advancing  tooth  to  go  into  place.  Should  the  temporary 
tooth  remain  too  long,  the  permanent  cuspid  will  work  its 


Fir..  32. 


way  either  inside  or  outside  the  arch,  as  illustrated  in  . 
32.  This  represents  the  lower  jaw  of  a  man  twenty-two 
years  of  age.  The  left  temporary  cuspid  is  in  position  and 
the  permanent  cuspid  has  erupted  inside  the  areh. 

The  retention  of  the  temporary  molars  is  a  fruitful  cause 
of  irregularities.  Fig.  32  also  illustrates  the  removal  of  the 
first  temporary  molar  and  its  place  filled  with  the  first  hicus- 
pid;  but  the  second  temporary  molars  are  in  place,  and,  as 
a  result,  the  second  bicuspid  upon  the  left  side  is  still  in 
the  jaw,  while  the  second  bicuspid  upon  the  right  side  has 
erupted  inside  of  the  arch  and  below  the  crown  of  the  u-m- 


PART   I — ANATOMY. 


61 


porary  molar.  Fig.  33  illustrates  a  case  in  practice  which 
is  one  of  the  most  difficult  to  correct.  It  is  the  upper  and 
lower  jaw  of  a  girl  ten  years  old.  The  temporary  teeth  are 
all  shed  from  the  lower  jaw,  and  the  first  permanent  molars 
have  come  forward  in  such  a  manner  that  they  prevent  the 
bicuspids  and  cuspids  erupting.  The  incisors  impinge  upon 
the  mucous  membrane  in  the  roof  of  the  mouth.  The  tem- 


FIG.  33. 


porary  cuspids  and  molars  are  still  in  position  upon  the  right 
side  of  the  upper  jaw,  and  the  second  molar  upon  the  left 
side.  The  first  bicuspid  is  just  making  its  appearance 
through  the  gum.  Had  the  temporary  teeth  been  extracted 
at  the  proper  time,  a  part  of  this  deformity  would  have  been 
prevented. 


CHAPTER  V. 

I K REGULARITIES  CAUSED  BY  TOO  EARLY  EXTRACTION  OF 
THE  TEETH. 

No  one  cause  which  can  be  controlled  by  tin-  dentist   is 

»nsible  for  so   much  irregularity  of  permanent    teeth 

as  the  premature  extraction  of  temporary  teeth.     It  is  an 

acknowledged  fact  that  temporary  teeth  require  great  care 

in  the  way  of  cleansing  and  filling. 

In  childhood,  the  size  of  the  jaw  anterior  to  the  first  perma- 
n  '-nt  molar  is  nearly  equal  to  that  of  the  adult;  the  growth 
continues  posterior  to  the  molars.  The  ten  temporary  teeth 
are  supplemented  by  the  same  number  of  permanent  teeth. 
Physiology  tells  us  that  the  members  of  the  body  must  he 
properly  exercised  to  become  strong  and  fully  developed. 
The  teeth  are  no  exception  to  this  rule.  Decay  of  «lc -eiduous 
teeth,  exposure  and  death  of  their  pulps,  and.  tinally.  extract- 
ing, render  the  act  of  mastication  difficult,  resulting  in 
inaction  of  the  jaws  and  arrested  development.  If  the 
deciduous  teeth  had  been  properly  cared  for  and  retained 
in  the  jaw,  they  would  have  acted  as  wedges  and  a»i>ted 
nature  in  enlarging  the  alveolar  process. 

It  is  claimed  that  the  jaws  are  not  retarded  in  their 
growth  by  the  extraction  of  the  temporary  teeth.  It  i-  a 
tact  that  can  be  easily,  demonstrated,  that  pressure  of  an- 
tagonizing teeth  assists  in  the  growth  of  the  jaw.  If  a  thread 
be  drawn  between  the  deciduous  teeth  regularly  each  day, 
and  increased  gradually  in  size,  it  will  be  observed  that  tin- 
spaces  between  the  teeth  will  increase,  showing  that  the 
p iv-sure  has  expanded  the  jaw.  When  a  temporary  tooth 
i»  extracted,  the  alveolar  process  which  formerly  surrounded 
it  has  no  further  function  and  is  absorbed.  The  jaw  1< 
a  certain  amount  of  tissue,  which  is  necessary  for  the  proper 
support  of  the  permanent  tooth,  and  the  diameter  of  the  jaw 

62 


PAET   I — ANATOMY.  63 

is  reduced,  producing  a  crowded  position  of  the  permanent 
teeth. 

The  temporary  teeth,  when  decayed,  should  be  rilled  and 
their  pulps  preserved  as  long  as  possible.  They  should 
never  be  removed  until  they  can  be  pushed  out  with  the 
finger,  or  until  the  permanent  tooth  makes  its  appearance. 
The  permanent  centrals  on  the  lower  jaw  commonly  appear 
posterior  to  the  temporary  centrals.  The  former  teeth  are 
so  much  the  larger  that  they  lap  over  the  edge  of  the  tem- 
porary laterals.  When  this  condition  exists,  the  temporary 
centrals,  and  not  the  laterals,  should  be  extracted.  The 
pressure  of  the  roots  of  the  centrals  against  the  laterals  will 
expand  the  jaws.  A  very  serious  mistake  is  the  extraction 
of  the  temporary  cuspids  to  make  room  for  the  lateral  iii- 
cisors.  The  temporary  incisors  being  much  smaller  than 
the  permanent,  when  the  first  teeth  are  shed  the  permanent 
incisors  are  not  only  crowded,  but  often  the  lateral  incisors 
are  obliged  to  erupt  inside  of  the  arch,  and  frequently  the 
dentist  extracts  the  cuspids  to  make  room  for  the  laterals  to 
go  into  place.  This  certainly  is  bad  practice,  because,  1st, 
the  anterior  part  of  the  jaw  will  not  be  properly  expanded, 
as  there  would  be  no  antagonism  of  the  teeth  to  produce 
pressure ;  2d,  the  laterals,  as  a  rule,  will  not  come  into  the 
arch ;  and,  3d,  the  bicuspids,  being  the  next  in  order  -of  erup- 
tion, make  their  way  forward  and  take  a  position  next  to 
the  laterals,  thus  preventing  the  permanent  cuspids  from 
coming  into  place. 

At  the  time  of  the  eruption  of  the  lateral  incisors,  absorp- 
tion of  the  roots  of  the  temporary  cuspids  has  not  commenced. 
Should  the  tooth  be  removed  at  this  period,  the  alveolar 
process  contracts  at  that  point,  which  will  reduce  the  size  of 
the  jaw,  the  permanent  cuspids  being  thereby  crowded  out. 

A  common  cause  of  irregularities  is  the  too  early  extrac- 
tion of  the  temporary  molars.  These  teeth  usually  decay 
early,  the  pulps  become  exposed  or  die,  and  abscesses  result. 
These  conditions  produce  pain,  and  the  teeth  are  sacrificed. 
Then  the  first  permanent  molars  gradually  work  forward 


r,  I  IRREGULARITIES   OF   THE   TEETH. 

ami  oeenpy  (lie  space  of  the  second  bicuspid  tooth,  the  bicus- 
pi.ls,  bring  the  next  teeth  to  erupt,  work  forward,  and,  when 
fully  erupted,  antagonize  with  the  lateral  incisors,  thus 
rrowding  out  the  cuspids,  which  are  the  last  to  make  their 
appearance. 

It  M  number  of  casts  of  the  jaws  were  examined  when  the 
temporary  molars  have  l»een  permanently  removed,  it  would 
be  seen  that,  in  the  majority  of  cases,  the  first  permanent 
molars  have  mme  forward  from  one-sixteenth  to  one-fourth  of 
an  inch,  and  have  crowded  the  permanent  teeth  anterior  to 
the  first  permanent  molar.  Some  writers  advance  the  idea 
that  when  the  first  permanent  molars  in  both  jaws  have 

Flo.  84. 


erupted  so  that  they  occlude,  this  will  prevent  forward 
progn-»ion ;  but  we  think  this  is  not  the  case.  These  teeth 
will  push  forward  until  they  meet  resistance.  As  before 
mentioned,  the  temporary  teeth  should  be  retained  until 
they  1  onsen  from  absorption  of  the  roots,  or  until  the  per- 
inanent  teeth  appear. 

Fig.  34  represents  the  upper  jaw  of  a  girl  ten  years  of  age. 
The  temporary  cuspids  and  the  first  and  second  molars 
upon  the  right  side  are  in  place,  thus  holding  the  first  per- 
manent molars  in  place,  while  upon  the  left  side  the  first 
and  second  molars  have  been  removed.  The  first  permanent 
molar  has  pushed  forward  a  quarter  of  an  inch,  making 


PART   I — ANATOMY.  65 

it  impossible  for  the  bicuspids  to  come  into  position.  This 
is  usually  the  case  with  children  whose  temporary  teeth 
have  been  removed.  The  first  permanent  molar  works  its 
way  forward  and  occupies  the  space  of  the  second  bicuspid, 
thus  crowding  the  anterior  teeth  out  of  place. 

FAILURE   OF   ANTERIOR   OCCLUSION. 

Want  of  occlusion  is  a  deformity  which  does  not  present 
itself  until  the  tenth  or  eleventh  year,  and  is  not  of  common 
occurrence.  Until  this  period  the  teeth  articulate  naturally. 
The  appearance  of  the  teeth  then  changes;  the  anterior 
teeth  do  not  occlude,  and  when  the  jaws  are  closed  quite  a 
space  is  observed.  This  irregularity  occurs  at  the  time  of 
development  of  the  first  or  second  molars,  which  erupt  at 
greater  length  than  the  anterior  teeth.  This  want  of  occlu- 
sion may  take  place  when  all  of  the  teeth  are  in  the  jaw,  or 
after  the  first  permanent  molar  has  been  extracted.  If  the 
teeth  are  all  in  the  jaw,  the  second  molar  may  pass  through 
the  jaw  farther  than  the  other  teeth,  as  a  result  of  the  patient 
sleeping  with  the  mouth  open,  thus  removing  the  pressure 
from  these  teeth,  or  the  bicuspids  are  prevented  from  erupt- 
ing their  natural  length  by  the  impingement  of  the  first 
permanent  molars  upon  them. 

Teeth  which  are  tender  upon  pressure,  caused  by  inflamed 
gums  or  death  of  pulp  and  peridental  inflammation,  or 
when,  from  decay,  pulps  are  exposed  and  thus  prevent  mas- 
tication on  account  of  pain,  do  not  occlude,  and  the  second 
molar  teeth  elongate.  When  the  first  permanent  molars  are 
extracted,  the  second  molars  tip  forward  and  the  posterior 
cusps  are  brought  up,  causing  them  to  strike  the  second 
molars  upon  the  upper  jaw,  and  thus  throw  the  jaws  apart. 
Such  a  case  is  illustrated  in  Fig.  35  (from  Dr.  A.  E.  Matteson's 
collection,  Chicago). 

PROTRUSION  OF  THE  UPPER  JAW. 

This  deformity  (Fig.  36)  does  not  manifest  itself  to  any 
extent  until  after  the  eruption  of  all  the  anterior  permanent 


gg  IRREGULARITIES  OF   THE  TEETH. 

teeth     The  question  of  the  teeth  having  spaces  lx-t 
thnii  or  being  crowded  together,  will  depend  upon  the  cause 
«,f  the  deformity.    In  some  cases  the  teeth  project  so  iar  that 
tin-  lips  cannot  cover  them  when  the  mouth  is  closed.    M  1  M -n 


FIG.  35. 


the  alveolar  process  is  involved,  there  is  a  fullness  of  the 
upper  lip  at  the  angle  and  septum  of  the  nose.  The  lower 
lip  passes  behind  the  superior  incisors  instead  of  covering 


I';..    H 


them.    There  are  many  causes  for  this  deformity  :  heredity, 

-i\f  development  of  the  superior  maxillary  hone,  exce* 

-i\v  <levelopment  of  the  alveolar  process,  forward  pressure  of 


PART   I — ANATOMY.  67 

the  incisor  teeth  by  deposition  of  bone  in  the  formation  of 
sutures,  pressure  produced  by  thumb-  or  lip-sucking,  arrested 
development  of  the  inferior  maxilla,  deformity  in  the  angle 
of  the  lower  jaw,  causing  the  teeth  to  occlude  back  of  the 
normal  bite,  forward  movement  of  the  teeth  produced  by 
lateral  pressure  of  the  molars,  bicuspids  and  cuspids,  Riggs' 
disease,  produced  by  tartar  and  other  irritants.  Any  or  all 
of  these  elements  may  be  causal.  The  incisors  are  some- 
times seen  at  an  angle  of  45  degrees  and  protruding  from 
between  the  lips.  This  is  seen  in  advanced  age.  In  most 
cases  an  irregular  development  of  the  alveolar  process  of  the 


FIG.  37. 


lower  jaw  is  seen.  The  molar  and  bicuspid  regions  being 
very  shallow,  the  incisor  and  cuspid  regions  are  correspond- 
ingly high,  or  the  molars  and  bicuspids  not  being  fully 
developed  in  the  posterior  part  of  the  mouth,  excessively 
developed  cuspids  and  incisors  are  found  in  the  anterior 
part  of  the  mouth.  In  either  case,  when  the  jaws  are  closed, 
the  incisors  are  forced  against  the  palatine  surfaces  of  the 
superior  incisors,  acting  upon  them  as  an  inclined  plane  and 
forcing  the  superior  incisors  forward.  When  a  tooth  or  teeth 
have  been  forced  in  a  given  direction,  even  after  the  power 
is  removed,  the  tendency  to  move  in  that  direction  continues. 


(J8  IRREGULARITIES   OF   THE   TEETH. 

PROTRUSION  OF  THE  LOWER  JA\V. 

This  deformity  (Fig.  37)  is  not  usually  very  marked,  and  is 
associated  with  the  permanent  teeth,  although  we  have  seen 
a  child  with  a  protruding  lower  jaw,  as  seen  in  Fig.  If,,  pe 

This  deformity  may  be  the  result  of  heredity,  of  inhar- 
monious development  of  the  jaws,  excessive  development  in 
the  body  of  the  lower  jaw,  want  of  harmony  in  the  develop- 
ment of  the  alveolar  process,  lack  of  development  in  the 
posterior  teeth,  and  excessive  development  in  the  anterior 
teeth  and  alveolar  process.  It  may  also  be  due  to  abnormal 
portion  of  the  follicles  of  the  incisors  in  the  alveolar  pro- 
cess, and  inattention  to  the  eruption  of  the  permanent  inci- 
sors. The  last  two  are  the  most  common  causes  of  this 
deformity.  When  the  incisors  make  their  appeanr 
through  the  gum,  the  crowns  are  directed  inward  and 
behind  the  inferior  incisors.  When  the  cutting  edges  have 
passed  posterior  to  the  inferior  incisors,  nature  cannot  cor- 
rect the  deformity;  it  can  be  improved  only  by  mechanical 
interference. 

IRREGULARITIES  OF  THE  TEETH  OF  IDIOTS. 

Dr.  Langdon  Down  first  called  the  attention  of  the  pro- 
ion  to  this  subject  in  a  paper  read  before  the  Odonto- 
logical  Society  of  London,  in  1871.  He  found  that,  with 
very  few  exceptions,  the  arches  of  congenital  idiots  w< 
contracted  in  width  between  the  bicuspids,  and  that  irregu- 
larity in  arrangement  of  the  teeth  was  the  rule  rather  than 
the  exception. 

Dr.  W.  \V.  Ireland  reports  that  from  eighty -one  idiots 
examined  thirty-seven  had  either  vaulted  or  Y-shaped 
arches.  When  these  reports  were  made  public,  Drs.  Kii 
ley.  of  NY\\-  York,  J.  W.  White  and  Stellwagen,  of  Philadel- 
phia, examined  the  mouths  of  the  inmates  of  idiotic  institu- 
tions upon  Randall's  Island  and  one  in  Pennsylvania.  Dr. 
Kingsley  observed  that  in  the  two  hundred  idiots  of  different 
nationalities  he  did  not  see  a  case  of  pronounced  V-shaped 
dental  arch,  and  but  few  cases  of  narrow  palatine  arch; 


PART   I — ANATOMY.  69 

that  he  found  but  three  or  four  saddle-shaped  palates.  Drs. 
White  and  Stellwagen  found  large,  well-shaped  jaws  the  rule. 
In  the  latter  reports  no  definite  statistics  of  the  proportion 
of  regular  and  irregular  jaws  and  teeth  are  given ;  con- 
sequently, the  accurate  condition  of  the  irregularities  of 
the  teeth  of  idiots  in  the  asylums  of  this  country  was  not 
known. 

The  author  has  endeavored  to  throw  some  light  upon  the 
subject,  and  has  made  extensive  and  thorough  examinations 
throughout  the  various  institutions  in  the  United  States. 
These  unfortunates  are  classed  differently  in  different  insti- 
tutions, according  to  the  degree  of  the  affliction ;  for  instance, 
one  asylum  divided  them  into  feeble-minded,  imbecile  and 
idiotic,  another  into  teachable  and  non-teachable,  etc.  For 
convenience  we  have  classed  them  as  high,  medium  and  low 
grades.  This  classification  was  the  simplest  for  the  super- 
intendents of  all  institutions. 

Two  classes  of  irregularities  were  observed — those  which 
developed  with  the  growth  of  the  individual  or  constitu- 
tional irregularities,  and  those  caused  by  local  conditions, 
and  found  in  the  jaws  of  strong-minded  individuals,  as, 
for  instance,  premature  extraction  and  the  retention  of 
temporary  teeth.  Those  only  were  noted  which  could  be 
classed  as  constitutional. 

These  examinations  were  conducted  by  the  author  where 
practicable,  and,  otherwise,  by  dentists  of  ability  practicing  in 
or  near  the  city  where  the  asylum  was  located.  They  filled 
out  blanks  prepared  for  this  purpose.  The  following  reports, 
however,  enable  us  to  estimate  the  condition  of  the  entire 
class : — * 

*  For  special  reports,  refer  to  "  ^Etiology  of  Irregularities  of  the  Teeth  and 
Jaws,"  read  before  the  Dental  Section  of  the  Ninth  International  Medical 
Congress,  held  in  Washington,  Sept.  5th,  1887. 


70 


IRREGULARITIES  OF   THE   TEETH. 


1  MILK  NO.  I. 
Total  Number  of  DEFORMITIES  IN  THE  JAWS  of  Both  Sexes. 

III'.  II  GRADE. 

No. 

Sex. 

N<  inn;*  !  . 

Large 
Jaw. 

1'iot  fusion 
Lower 
Jaw 

Protrusion 
Upper 

.law. 

p, 

An 

i!1 

jl 

!|i 

Thiiinb- 
suckiug. 

Ifl 

Small 
Teeib. 

225 

in 

Male, 
female. 

115 

101 

21 
11 

5 
8 

21 
9 

61 
40 

11 

13 

30 
9 

2 
6 

38 
20 

7 
8 

loo 

82 

18 

30 

101 

24 

aa 

7 

68 

U 

MIDDLE  GRADE. 

874 
274 

Male. 
Female. 

246 

10 
10 

15 
6 

13 
6 

32 
19 

21 
12 

39 
43 

1 
5 

26 
19 

11 

648 

20 

21 

19 

61 

88 

82 

6 

45 

* 

LOW  GRADE. 

214 
843 

M,I.;. 

72 

20 
15 

15 
14 

24 
24 

46 
40 

27 
13 

84 
45 

7 
11 

29 
27 

9 
9 

5*7 

279 

35 

29 

48 

86 

40 

79 

18 

56 

lit 

TABLE  NO.  II. 
Total  DEFORMITIES  IN  THE  JAWS. 

No. 

Normal,      j^2f* 

Protrusion 
Lower 
Jaw. 

jl* 

High 
Arch. 

i  . 
J1 

ill 

Thumb- 
suck  ing. 

ft 

Sum!! 
Teeth. 

1605 

924            87 

63 

97 

238 

101 

200 

81 

159 

H 

Examinations  were  made  in  the  following  institutions: 
Asylum  for  Idiots  of  the  State  of  New  York,  Syracu- •: 
Massachusetts  School  for  Feeble  Minded,  South  ]><><i'm: 
Illinois  Asylum  for  Feeble-minded  Children,  Lincoln; 
. \-yluiii  for  Idiots,  Randall's  Island;  Minnesota  Training 
School  for  Idiots  and  Imbeciles,  Faribault;  Kansas  Stak- 
m Asylum  for  Idiots  and  Imbecile  Youth,  Winlidd;  Cook 
County  Insane  Asylum,  Dunning,  111;  Penn  Institute  for 
rVrl.lr-niindril  Children,  Khvyn. 

It  will  be  acknowledged  that  in  an  equal  number  <>f 
strong  ami  feeble-minded  persons  the  larger  percentage  <»f 
irregularities  is  found  in  the  hitter  class.  These  deformities 


PART   I — ANATOMY.  71 

do  not  confine  themselves  to  V-,  saddle-shaped  and  high 
arches,  but  statistics  show  a  very  large  percentage  of  arrested 
development  of  maxillary  bone,  partial  V-shaped  arch,  ex- 
cessive growth  of  the  superior  maxilla,  and  protruding  supe- 
rior and  inferior  jaws.  These  abnormal  conditions  of  jaw 
are  developed  in  harmony  with  other  abnormal  tissues  of 
the  individual :  as  arrested  development  of  external  and 
internal  organs,  nerve  tissue,  excessive  growth  of  tissue. 
Since  the  above  report  was  tabulated  we  have  visited  the 
Penn  institution  of  feeble-minded  children  at  Elwyn,  where, 
with  the  assistance  of  Dr.  Wilmarth,  a  critical  examination 
was  made  of  the  mouths  of  microcephalous  and  macroceph- 
alous inmates  numbering  about  forty-eight.  Out  of  twenty- 
eight  microcephalous  children,  all  excepting  one  had  small 
maxilla?,  while  twenty -three  out  of  the  twenty-six  macro- 
cephalous had  well-developed  jaws.  These  observations  agree 
with  those  made  by  Dr.  Langdon  Down,  in  1871.  The  teeth 
of  the  microcephalic  children  were  irregular  and  crowded, 
the  alveolar  process  in  most  cases  being  larger  than  the  bone 
proper,  and  its  irregular  shape  conforming  to  the  position  of 
the  teeth.  While  the  alveolar  process  of  the  macrocephalic 
cases  was  on  a  line  with  the  maxilla,  with  sufficient  room 
for  the  development  of  the  teeth,  and  in  some  cases  with 
spaces  between  them,  the  majority  of  the  former  grade  of 
beings  have  a  marked  constriction  in  the  jaws  at  the  bicus- 
pid region. 


PART  II-TREATMENT. 


CHAPTER  I. 

THE  PROPER  PERIOD  FOR  REGULATION. 

The  proper  period  at  which  to  begin  operative  interference 
in  cases  of  irregularity  is  of  paramount  importance,  if  Ave 
desire  to  obtain  the  most  perfect  results;  but  in  deciding 
the  question  the  following  conditions  must  be  considered: 
1st.  The  character  of  the  deformity,  the  age,  health  and  sex 
of  the  patient.  2d.  Many  irregularities  are  so  slight  that,  if 
uninterfered  with,  nature  will,  in  the  majority  of  instances, 
accomplish  much  better  results  than  the  ill-advised  efforts  "t 
the  dentist,  e.g.,  the  cuspids  and  incisors  quite  frequently 
erupt  out  of  their  position,  but  gradually  find  their  proper 
places. 

3d.  There  are  other  cases  in  which  a  moderate  amount  of 
asymmetry  of  development  has  been  produced  by  some 
imperfect  or  irregularly  erupted  tooth,  which,  being  of  slight 
importance  in  itself,  may  with  propriety  be  removed.  This 
conservatism  is  often  attended  by  results  as  good  as  could  be 
desired.  If,  therefore,  the  teeth  are  carefully  watched  by  a 
competent  dentist  from  the  time  of  their  eruption  until  they 
are  fully  developed,  the  necessity  of  operations  for  the  cor- 
rection of  irregularities  in  later  life  is  reduced  to  a  mini  mum. 

4th.  As  illustrative  of  this  fact,  it  may  be  stated  that  it  one 
or  more  of  the  anterior  superior  incisors  exhibit  a  tendency 
to  occlude  posteriorly  to  the  cutting  edges  of  the  inferior 
teeth,  this  may  be  easily  corrected  as  soon  as  they  appear 
through  the  gum.  We  may  thus  in  a  very  simple  manner 
correct  deformities  which,  if  neglected,  would  sooner  or  later 
require  the  best  of  knowledge  and  mechanical  skill  and  no 

72 


PART    II — TREATMENT.  73 

end  of  trouble  to  remove.  Aside  from  this  simple  abnor- 
mality, however,  irregularities  of  the  incisors  had  best  be  let 
alone  until  after  the  cuspids  have  erupted. 

In  fact,  if  any  of  the  teeth  posterior  to  the  lateral  incisors 
are  involved,  even  in  the  simple  deformity  just  mentioned, 
it  is  wise  to  defer  interference  until  after  both  the  cuspids 
and  bicuspids  have  erupted.  Their  relative  positions  can 
thus  be  studied,  and  with  a  single  operation  their  symmetry 
can  be  restored.  Occasionally,  perhaps,  an  earlier  operation 
would  be  advisable,  but  the  above  rule  may  be  considered 
the  safest  in  the  larger  proportion  of  cases. 

From  preceding  considerations  it  may  be  readily  observed 
that  no  arbitrary  rule  as  to  the  precise  time  for  interference 
can  be  safely  given/  On  the  average,  however,  it  may  be 
said  approximately  that  the  best  time  for  interference  in  the 
majority  of  cases  is  from  the  twelfth  to  the  fourteenth  year. 
At  this  time,  the  transitional  period  between  childhood  and 
puberty,  all  of  the  teeth  are  erupted,  general  nutrition  is 
most  active,  the  osseous  system  is  in  the  constructive  stage, 
and  the  formative  process  is  in  vigorous  operation.  At  this 
time,  also,  the  roots  of  the  teeth  are  not  fully  developed,  but 
are  more  or  less  loosely  confined  within  the  alveoli,  and  the 
apical  foramina  are  large,  thus  lessening  the  liability  of 
impairment  of  the  blood  supply  and  consequent  destruction 
of  the  pulp. 

The  conditions  mentioned  as  existing  at  the  twelfth  to  the 
fourteenth  year  being  coincident  with  the  completion  of  the 
eruption  of  the  teeth,  it  naturally  follows  that  the  reverse 
holds  true ;  hence,  in  any  case  in  which  the  teeth  are  fully 
erupted,  we  may  proceed  to  operate  irrespective  of  the  age  of 
the  patient. 

The  probability  of  a  perfectly  satisfactory  result  in  regu- 
lating decreases  yearly  after  the  age  of  puberty,  and  after  the 
age  of  twenty-six  the  chances  of  a  really  satisfactory  result 
are  very  meagre ;  for  at  this  time  the  entire  osseous  system  is 
fully  developed,  and  there  is  little  probability  of  extensive 
deposit  of  ossific  material.  It  is  possible  to  regulate  deformi- 


74  IRREGULARITIES   OF  THE  TEETH. 

ties  even  as  late  as  tin-  thirtieth  year,  but  tin-  iv>ulting  ])ain 
•  •IT.  ami  tin-  mechanical  force  necessary  to  produce 
absorption  of  the  obstnu-tivc  portions  of  tin-  alveoli  is  so 
great,  that  the  end  hardly  justifies  the  means.  AVhen  regu- 
lated  so  late  in  life,  retentive  and  corrective  plate-  mu>t  l.e 
worn  tor  years  to  hold  the  teeth  in  place  until  ossific  matt- 
rial  shall  have  formed  to  retain  them  in  their  new  position. 

In  some  cases  of  late  correction,  absorption  of  the  alveolar 
process  not  being  followed  by  compensatory  ossific  depo>it. 
the  merhaniral  interference  produces  chronic  inflammation 
of  the  peridental  membrane,  i.  e.,  a  veritable  pyorrhoea  ah 
lari.s.  I  observed  this  very  condition  in  the  mouth  of  a  lady 
of  thirty-live,  in  whom  an  extended  and.  I  may  add,  ill- 
advised  operation  had  been  performed.  If  the  teeth  must 
be  regulated  at  this  period  of  life,  the  operation  should  he 
conducted  with  great  caution  and  the  patient  should  he  duly 
impressed  with  a  doubtful  prognosis.  When  the  patient 
insists  upon  an  attempt  at  regulation,  and  is  willing  to 
assume  the  responsibility  of  failure,  we  are  perhaps  just  i  tied 
in  operating  in  any  case  of  reasonable  age. 

Having  considered  in  detail  the  proper  period  for  regu- 
lating, we  are  confronted  with  another  question  of  perhap- 
great  importance,  viz.,  the  general  health  and  constitutional 
peculiarities  of  the  patient.  Inasmuch  as  the  majority  of 
cases  for  regulation  are  youthful,  this  matter  of  the  general 
health  is  no  slight  consideration.  It  is  an  unfortunate  fact 
that  the  most  favorable  period  for  operation  is  one  of  t In- 
most critical  in  the  life  of  the  patient,  so  far  as  the  general 
health  is  concerned. 

From  the  age  of  twelve  to  sixteen,  the  rapidly-growing 
boy  or  girl  is  subjected  to  many  physical  changes,  entailing 
profound  disturbances  of  the  general  and  trophic  nei\ 
systems.  Prolonged  and  injudicious  hours  of  study,  over- 
:  tion.  had  air,  improper  or  insufficient  food,  sexual  irrita- 
tion, and  many  other  disturbing  elements,  are  apt  to  become 
prominent  factors  in  the  daily  life  of  the  patient. 

The  matter  of  sexual  disturbance  is  of  especial  importance 


PART    II — TREATMENT.  75 

in  females,  on  account  of  the  new  function — menstruation 
—which  asserts  itself  at  this  period.  When  we  superadd  to 
these  physiological  perturbations  and  circumstances  of  envi- 
ronment, the  perversion  of  nutrition  consequent  upon  con- 
genital weakness,  rachitis,  hereditary  syphilis  or  the  exanthe- 
mata, the  important  bearing  of  the  condition  of  the  general 
health  upon  our  operative  procedures  is  very  manifest.  We 
should  defer  operating,  therefore,  on  young  persons  in  deli- 
cate health  until  such  time  as  they  have  become  improved 
by  proper  treatment ;  and  it  behooves  us  as  scientific  dentists 
to  know  something  of  these  general  conditions,  so  that  we 
may,  in  all  conscientiousness,  place  them  in  proper  hands  for 
constitutional  treatment.  It  is  in  just  such  cases  as  these 
described  that  the  cooperation  of  a  skillful  physician  is  indis- 
pensable. A  case  was  recently  noted  in  this  city  where,  from 
a  prolonged  operation  in  regulating,  a  delicate,  pun}r  lady 
was  invalided  for  two  years,  solely  by  the  shock  produced 
upon  a  nervous  system  primarily  unstable. 

PHYSIOLOGICAL  AND  PATHOLOGICAL  CHANGES. 

It  is  apparent,  to  a  close  observer,  that  the  teeth  are  con- 
stantly changing  their  positions  in  the  jaw,  absorption  and 
deposition  of  bone  going  on  simultaneously  and  continu- 
ously. This  is  particularly  noticeable  at  the  first  eruption  of 
the  teeth,  and  again  from  the  twelfth  to  the  sixteenth  year. 
When  the  first  permanent  molar  has  been  removed,  the 
second  and  third  gradually  press  forward  and  fill  the  space. 

It  will  also  be  noticed  that  teeth  that  are  erupted  out  of 
their  position  will,  in  time,  often  find  their  way  into  their 
proper  places  ;  also,  when  the  molars  and  bicuspids  are  lost 
late  in  life,  the  anterior  teeth  are  forced  forward,  thus  causing 
the  alveolar  arches  to  project.  Again,  it  is  found  that  when 
the  anterior  teeth  come  in  irregularly,  they  rotate  their  way 
into  place.  These  facts  indicate  that  when  nature  is  assisted, 
whether  by  mechanical  devices  or  the  removal  of  obstruc- 
tions, the  regulation  of  malpositions  becomes  both  simple  and 
logical :  and,  furthermore,,  that  after  regulation,  the  teeth 


7«;  IRREGULARITII>    <-l     THK    TEKTH. 

innv  IM-  firmly  retained   in   their  relatively  new  positions  in 
tin-  alveolar  |.r<.eess. 

It  -land-  tii  iva-oii  that  tlie  application  of  light,  constant 
pivs-ure  t<»  irregular  teeth,  in  connection  with  nature'-  own 
efforts,  will  greatly  enhance  the  physiological  phenomena  of 
absorption  and  reproduction  of  hone.  Whether  these  phe- 
nomena will  jiroeeed  equally  or  not  will  depend  npon  the 
amount  of  pressure  exerted  and  the  condition  of  the  individ- 
ual, for  it  is  olivioiis  that  in  cachexia-  of  various  kinds 
disintegration  is  favored,  while  tissue-building  is  correspond- 
ingly sln^ish.  This  will  serve  to  impress  the  immediately 
vital  importance  of  the  degree  of  jiressure  and  the  constitu- 
tional condition  of  the  patient  in  various  operation-  of  regu- 
lating. When  the  whole  of  the  alveolar  arch  i>  -pr«-ad  later- 
allv.  and  the  force  is  distributed  fora  distance  upon  both 
side-  of  the  jaw,  the  hones  yield  to  a  certain  extent,  thus 
spacing  the  teeth  equally  in  all  directions;  and  by  ah-orp- 
tion  of  the  old  and  deposition  of  the  new  bone  about  them, 
they  heroine  fixed  in  their  new  positions.  The  degr< 
absorption  and  change  of  position  is  not  always  equal  in  all 
part- of  the  same  tooth,  varying  chiefly  with  the  direction 
of  the  pressure. 

When  force  is  applied  to  the  crown,  and  the  tooth  has 
to  he  moved  considerably,  there  is  more  absorption  at  the 
margin  of  the  alveolus  than  at  its  apex.  Simple  leverage 
will  explain  this:  the  mechanical  appliance  is  the  power,  and 
the  apex  of  the  tooth  is  the  fulcrum  :  naturally,  the  pow.-r 
acts  up<m  the  margin  of  the  cavity  in  which  the  tooth  is 
imbedded.  Or,  it  might  be  said  that  the  tooth  moves  like  a 
spoke  in  a  wheel :  the  outer  part  of  the  crown  travels  a  rela- 
tively greater  distance  than  the  inner  part,  or  apex.  The 
gradual  diminution  in  diameter  from  neck  to  apex  is  also 
an  important  consideration. 

When  the  pre>-ure  i-  too  great,  then  absorption  is  arrested, 
•  »n  account  of  the  inflammation  ami  pain  which  result. 
The  operator  -hotild  avoid  causing  pain,  and  this  is  usually 
|>o<-ihle.  When  paindoesoecur.it  should  warn  him  that 


PART   II — TREATMENT.  77 

the  line  of  demarcation  between  physiological  and  patho- 
logical changes  is  being  transgressed  by  mechanical  violence. 
If  the  pressure  be  gentle,  evenly  distributed  and  constant, 
no  pain  will  be  experienced  after  the  teeth  have  once  begun 
to  yield  in  the  proper  direction.  But  when  the  force  is 
applied,  removed,  and  reapplied  at  spasmodic  intervals,  con- 
siderable pain  must  necessarily  result. 

The  difference  between  the  effects  of  steady  and  those  of 
intermittent  pressure  is  illustrated  in  every-day  practice: 
where  teeth  have  been  separated  to  facilitate  the  filling  of 
proximate  cavities,  the  vibration  of  the  teeth  caused  by 
preparing  the  cavity  and  applying  the  gold  produces  intense 
pain,  which  is  relieved  by  inserting  a  wedge  to  distend  and 
steady  the  teeth  by  its  constant  and  equable  pressure.  Indi- 
vidual susceptibility  must  not  be  forgotten  in  this  connec- 
tion ;  for,  as  is  well  known,  the  impressibility  to  pain  and 
the  power  of  endurance  vary  with  the  temperament  and 
condition  of  the  patient.  After  the  age  of  twenty-five  or 
six  the  bones  contain  more  of  the  earthy  and  less  of  the 
animal  matter  than  during  the  formative  and  developmental 
period,  and  the  constructive  stage  having  passed,  it  becomes 
more  difficult  to  move  the  teeth  than  in  earlier  life;  and, 
•pari  passu,  with  the  increased  pressure  required  to  effect 
absorption,  a  greater  degree  of  pain  and  inflammation  is 
produced. 

In  these  latter  cases  of  regulating,  retentive  plates  must 
often  be  worn,  after  the  malposition  of  the  teeth  has  been 
corrected,  for  two  or  three  years,  until  a  deposition  of  bone 
takes  place  which  is  sufficiently  firm  to  hold  the  teeth 
securely  in  place.  The  teeth  most  difficult  to  retain  are  those 
that  have  been  rotated  in  the  jaw,  as  they  have  a  tendency 
to  return  to  their  original  and  faulty  positions  even  after  a 
lapse  of  three  years.  By  dispensing  with  the  retentive  plate 
for  a  day  or  two,  and  then  reinserting  it,  any  deviation  in 
position  can  be  readily  noted. 


7>  IRREGULARITIES   OF   THE  TEETH. 

EXAMINATION  OF  THE  TEETH. 

When  an  abnormal  condition  of  the  jaw  and  teeth  is  pre- 
sented for  examination,  the  nicest  discernment  is  necessary 
to  decide  tin-  best  course  of  regulating.  A  dentist  pn-<e>sed 
with  ordinary  intelligence  has  no  difficulty  in  correcting  an 
insularity  when  a  few  teeth  are  out  of  position,  but  when 
tin-  jaw-  ami  teeth  are  both  involved,  and  the  features  are 
atlected  thereby,  the  question  becomes  one  in  which  judg- 
ment is  necessary.  That  dentists  are  rarely  able  to  con<iu« -r 
this  problem  is  not  to  be  wondered  at  when  AY.  consider 
the  limited  amount  of  instruction  given  in  most  text- 
books and  colleges.  The  mouth  is  one  of  the  most  <  \| 
si YC  tea tu res:  more  than  any  of  the  other  features  of  the 
lace  it  indicates  age  and  characterizes  the  race  to  which 
it  belongs. 

The  teeth  are  not  developed  into  type  peculiarities  until 
the  time  of  puberty,  so  that  regulating  should  be  delayed  as 
long  as  i<  compatible  with  safety,  to  allow  nature  to  arrange 
the  teeth  as  tar  as  possible  before  interfering  with  them. 
Thus,  nature  frequently  corrects  extensive  irregularities,  if 
left  to  herself.  The  facilities  for  regulating  are  now  >o  much 
improved  that  there  is  no  excuse  for  allowing  deformities  to 
remain,  even  though  they  be  inherited. 

Speech  is  often  interfered  with  by  the  contraction  of  the 
jaws.  The  upper  or  lower  jaw,  or  both,  may  be  so  narrow 
at  the  bicuspid  region  that  the  tongue  is  forced  into  the 
fauces.  The  roof  of  the  mouth  may  be  high  and  narrow  or 
flat  and  shallow;  the  natural  or  supernumerary  teeth  may 
point  in  such  a  direction  that  the  tongue  cannot  move  pro- 
perly. The  incisors  may  be  so  separated,  or  the  teeth  may 
be  so  proportionately  small,  as  to  produce  spaces  >utlieicnt 
to  affect  the  speech. 

DECAY  OF  THE  TEETH. 

In  frail,  anemic  patients,  it  is  often  wise  to  extract  a  tooth 
from  either  side  of  the  jaws,  when  the  teeth  are  crowded  and 
decay  is  rapidly  going  on  between  them.  Which  tooth  to 


PART   II TREATMENT.  79 

remove  will  depend  upon  circumstances.  Those  most  decayed 
or  nearest  the  deformity  are  the  ones  to  be  removed. 

If  a  molar  be  badly  decayed  upon  one  side  and  a  bicuspid 
upon  the  other,  they  should  be  removed.  The  condition  of 
the  teeth  must,  to  a  great  extent,  govern  the  operation.  The 
dentist  must  decide  in  each  particular  case. 

OCCLUSION. 

While  the  model  is  the  surest  and  easiest  means  of  study- 
ing the  occlusion  of  the  teeth,  the  final  conclusions  can  be 
drawn  from  the  mouth;  hence  this  part  of  the  subject  will  be 
taken  up  here.  It  has  been  shown  how  the  teeth,  which  are 
nearly  always  normal  in  size,  work  their  way  through  the 
jaws  and  arrange  themselves  along  the  alveolar  process. 
These  teeth  developing  individually,  it  would  be  natural  to 
expect  that  in  occluding,  the  cusps  of  the  teeth  upon  one 
jaw  would  not  fit  into  the  spaces  in  the  teeth  of  the  opposite 
jaw.  This  being  the  case,  owing  to  the  constructive  stage  of 
the  alveolar  process,  the  teeth  will  arrange  themselves  to 
conform  to  the  articulation  of  the  opposite  teeth.  The  teeth 
all  being  in  the  jaws,  and  the  mesial  and  distal  surfaces  of 
all  the  teeth  touching,  if  the  articulation  be  not  perfect  the 
teeth  will  rotate  in  their  sockets.  If  spaces  exist  between 
the  teeth,  they  will  change  their  position  until  the  proper 
occlusion  is  obtained. 

We  sometimes  find  the  buccal  cusp  of  one  tooth  striking 
the  buccal  or  lingual  cusp  of  the  tooth  opposite.  In  such 
cases  one  or  the  other  is  deflected  in  or  out  of  the  mouth. 
To  correct  these  cases  it  may  be  necessary  to  extract  a  tooth, 
or  cut  away  a  cusp  or  the  approximal  surfaces  of  the  teeth 
in  order  to  cause  occlusion.  Lastly,  an  examination  should 
be  made  of  the  shape  and  contour  of  the  jaws,  the  height  of 
the  arch,  and  the  inclination  of  the  teeth,  to  decide  upon  a 
suitable  impression  cup  and  the  best  material  for  taking 
impressions. 


80  IRREGULARITIES   OF   THE   TEETH. 

0 

FEES. 

In  most  cases  an  important  consideration  in  the  operation 
Dilating  u  net  of  teeth  is  the  pecuniary  reward  for  it. 
Tin-  specialist  in  this  particular  branch  should  lia 
prepared  himself  that  hr  will  fully  understand  and  appreci- 
ate the  requirements  of  any  case  which  he  may  undertake 
to  correct.  To  do  this  will  take  much  time  and  anxious 
thought,  for  which  he  should  receive  a  just  reward.  A  thor- 
ough understanding  as  to  the  proper  remuneration  for  the 
operation  should  he  estahlished  between  the  dentist  and  his 
patient  before  anything  is  done. 

The  models  of  the  jaws  should  be  carefully  examined. 
The  temperament  and  disposition  of  the  patient,  as  well  as 
the  ossific  condition  of  the  jaws,  should  be  considered  and 
minutely  inquired  into.  For  it  will  frequently  happen  that 
mouths  exhibiting  very  nearly  the  same  deformity  will,  on 
account  of  mental  and  physiological  idiosyncrasies  and  great 
difference  in  density  of  tissue,  require  very  different  treat- 
ment in  order  to  accomplish  equally  favorable  results.  After 
these  preliminaries  have  been  carefully  attended  to.  a<  c,.r- 
reet  an  estimate  as  possible  should  be  made  (and  at  the  best 
it  can  but  approximate)  of  the  expense  of  regulating  the 
teeth  and  securing  them  in  their  proper  position. 

At  this  juncture,  and  before  any  operation  is  begun,  a 
thorough  understanding  should  be  established  between  the 
operator  and  the  parent  or  guardian  of  the  approximat- 
of  the  work.  It  is  well  not  to  be  too  definite  in  regard  to  the 
matter;  for  it  will  frequently  happen  that  the  operation  will 
require  very  different  appliances  and  consume  more  time 
than  was  at  first  anticipated,  in  which  case  the  operator 
should  be  rewarded  for  his  unexpected  labor.  Or,  the  oj  .era- 
tion  may  be  completed  in  a  much  shorter  time  than  was 
anticipated,  in  which  event  a  proper  regard  for  the  patient's 
rights  should  prompt  a  reduction  in  the  fee.  A  minimum 
and  a  maximum  price,  therefore,  should  be  agreed  upon 
before  the  operation  is  undertaken.  Conspicuous  among  the 
difficulties  which  come  with  regulating  is,  first,  to  persuade 


PART   II — TREATMENT.  81 

the  patient  to  submit  to  the  annoyance  of  wearing  the 
appliance  ;  and,  secondly,  to  impress  upon  the  patient  the 
necessity  of  being  prompt  and  faithful  in  his  visits  to  the 
dentist.  Not  appreciating  the  importance  of  these  opera- 
tions, patients,  and  especially  children,  frequently  become 
discouraged,  and  are  anxious  to  abandon  the  treatment  be- 
fore it  is  completed.  The  parent  too  often  sympathizes  with 
the  child,  and  without  regard  for  the  labor  or  expense  which 
the  dentist  has  assumed,  or  the  real  interest  of  the  patient, 
the  operation  is  abandoned.  The  dentist  is  left  without 
remuneration,  although  up  to  this  point  he  has  carried  out 
his  part  of  the  contract.  To  secure  the  continued  coopera- 
tion of  the  patient  and  parent  until  the  completion  of  the 
operations,  it  is  but  justice  to  the  dentist  that  he  should 
demand  and  receive  at  least  one-half  of  the  proposed  fee 
before  the  work  is  begun.  With  this  money  invested  in  the 
operation,  the  parent  will  be  loth  to  allow  the  case  to  be 
abandoned  before  it  is  finished. 

The  dentist  should,  with  due  regard  to  the  comfort  and 
good  of  his  patient,  do  all  in  his  power  to  expedite  his 
operation,  so  that  the  suffering  and  expense  may  be  as  light  as 
possible ;  but  whatever  he  does  should  be  done  with  an  in- 
telligent understanding  of  the  physiological  and  pathological 
conditions  with  which  he  is  dealing.  The  patient  should, 
by  obedience  to  the  dentist's  instructions,  do  all  in  his  power 
to  facilitate  the  correction,  which  will,  as  a  matter  of  course, 
greatly  reduce  the  expense  of  the  operation.'  As  a  rule,  it 
will  be  better  not  to  be  too  minute  in  detailing  the  plans 
intended  to  be  followed  and  the  appliances  to  be  used  in  the 
course  of  the  operation,  for  it  will  frequently  happen  that 
the  most  carefully-planned  procedure  will  have  to  be  varied 
during  the  operation;  in  which  case  disappointment  and 
dissatisfaction  might  be  engendered  in  the  mind  of  the 
patient,  and  lead  to  a  suspicion  as  to  the  dentist's  ability  to 
accomplish  the  results  at  first  promised. 


CHAFfER  II. 

I.MI'UKSSinNS  <)F  THE  MOUTH,  AND  MODELS. 

Taking  the  impression  of  the  mouth  and  jaws  is,  of 
necessity,  the  first  step  in  regulating  the  teeth.  To  secure  a 
counterpart  of  tin-  mouth  sufficiently  accurate  for  reference 
and  study,  so  that  when  a  model  is  examined  it  will  show 
\act  contour  of  the  irregularity,  requires  much  can, 
The  |>osition  of  the  teeth,  their  relations  to  one  another,  and 
the  conformation  of  the  jaws  can  be  more  easily  studied,  and 
accurate  conclusions  more  readily  deduced,  from  the  cast 
than  from  an  examination  of  the  mouth  itself.  It  is  not 
only  essential  that  the  teeth  should  be  moved  to  their  proper 
places,  hut  they  must  be  in  harmonious  relation-  to  one 
another;  otherwise,  they  will  be  inclined  to  return  to  their 
faulty  positions:  and  their  normal  relations  can  best  be 
determined  by  studying  the  model. 

Impressions  may  be  taken  in  plaster-of-Paris  or  in  model- 
ing compound,  but  the  material  employed  should  depend  to 
a  great  degree  upon  the  shape  of  the  jaw  and  the  position  of 
the  teeth.  If  the  teeth  are  but  slightly  irregular,  or  if  the 
crowns  are  short  and  quite  irregular,  plaster-of-Paris  should 
be  used,  as  it  can  be  removed  from  the  mouth  with  but 
little  disturbance  of  the  impression. 

If,  on  the  other  hand,  the  teeth  are  irregular  and  long, 
and  the  arch  deep,  plaster-of-Paris  wrill  be  apt  to  adhere  to 
the  teeth;  in  this  event  only  the  impression  cup  will  come 
away,  and,  as  a  consequence,  the  plaster  will  have  to  be  cut 
out.  In  such  cases  the  modeling  compound  should  be  used. 

Where  the  plaster  is  used  the  patient  should  occupy  an 
ordinary  chair  instead  of  the  operating  chair,  as  the  head  is 
lower  and  the  operator  can  have  better  control  of  the  patient. 
Protect  the  clothing  by  placing  two  towels  under  the  chin 
and  a  newspaper  in  the  lap.  Select  an  impression  cup 

82 


PART   II — TREATMENT.  83 

enough  to  enclose  the  teeth,  and  build  it  up  with  wax  so 
that  it  will  extend  beyond  the  margin  of  the  gums  ;  fill  the 
centre  of  the  cup  with  soft  wax  to  conform  to  the  palate ;  and 
the  plaster  will  be  readily  carried  to  all  parts  of  the  mouth. 
Take  a  quantity  of  the  finest  quality  of  plaster,  and  mix  it 
in  a  bowl  with  sufficient  water  to  make  a  mixture  of  the 
consistency  of  thick  cream ;  the  addition  of  a  little  salt  will 
hasten  the  process  of  setting.  After  stirring  until  the  air 
bubbles  have  disappeared  and  the  plaster  has  begun  to  set, 
fill  the  cup  and  outer  edges  with  it. 

The  operator  should  stand  to  the  right  of  and  just  behind 
the  patient,  with  the  left  arm  around  the  left  side  of  the 
head,  and  the  forefinger  inserted  into  the  mouth.  Carry 
the  cup  to  the  mouth,  with  the  thumb  and  forefinger  upon 
the  handle  and  the  middle  finger  in  the  centre  to  steady  it, 
and  after  it  has  been  inserted  into  the  mouth,  with  a  rotary 
motion  of  the  right  hand  press  it  into  place,  at  the  same 
time  raising  the  lip  and  pressing  out  the  cheek  with  the 
left  finger.  When  the  cup  is  in  position,  hold  it  firmly  with 
the  middle  finger  in  the  centre  of  the  plate  against  the  teeth. 
Incline  the  head  towards  the  breast  to  prevent  the  plaster 
passing  back  to  the  fauces.  Should  the  stomach  become 
disturbed,  and  vomiting  ensue,  it  can  be  evacuated  without 
interfering  with  the  impression. 

Test  the  plaster  in  the  bowl  or  on  the  impression  cup, 
and  when  it  will  break  with  a  clean  fracture,  it  is  time  to 
remove  the  cup,  which  can  be  done  by  moving  the  cup 
backward  and  forward  with  the  right  hand,  and  pushing  out 
the  cheek  with  the  fingers  of  the  left  hand  to  admit  the  air. 
Having  placed  it  in  the  upper  towel,  held  up  by  the  assist- 
ant, carefully  examine  the  mouth,  and  if  pieces  of  plaster 
are  seen,  put  them  in  the  towel  on  the  proper  side  of  the 
impression  to  save  time,  and  set  it  carefully  away,  after- 
wards arranging  the  pieces  in  their  right  places  in  the 
impression. 

The  second  towel  is  for  the  purpose  of  removing  plaster 
that  may  remain  about  the  face. 


84  IRREGULARITIES   OF    THE   TEETH. 

It  is  well  to  explain  something  of  the  operation  to  the 
patient.  ;is  one  would  naturally  anticipate  a  m«»iv  serious 
experience  than  is  actually  realized.  All  of  these  little  de- 
tails should  he  strictly  attended  to,  in  order  to  insure  a  per- 
fect impression  at  the  first  sitting,  and  thus  save  the  patient 
the  annoyance  of  several  applications. 

In  taking  impressions  of  the  lower  jaw,  the  patient  should 
Mt  higher,  so  that  the  mouth  will  he  on  a  level  with  the 
rlhow  of  the  operator,  who  stands  in  front  of  the  patient: 
the  fingers  of  the  left  hand  should  push  out  the  cheeks 
and  lips  while  the  cup  is  rotated  into  place  with  the  ri-ht 
hand.  The  first  and  second  finger  of  each  hand  should 
iv- 1  upon  the  cup  over  the  bicuspids  and  molars,  the 
thumhs  under  the  jaw  on  either  side,  thus  holding  the  cup 
firmly  in  place  until  the  plaster  sets,  when  it  should  he 
removed  and  placed  in  the  towel  as  before.  After  a  few 
minutes'  hardening,  the  impression  should  be  placed  under 
running  water  to  remove  mucus,  saliva,  blood  or  particles  <.f 
plaster.  Should  the  plaster  he  broken,  the  piece  can  l.e  placed 
in  the  positions  indicated  by  the  arrangement  on  the  towel. 
and.  when  perfectly  dry.  fastened  together  by  melted  black 
wax.  A  clean  separation  of  the  model  is  obtained  by  covering 
it  with  a  lather  of  soap  and  washing  off  the  Mirpliis,  or  by 
coating  with  shellac  and  oiling  to  prevent  sticking. 

The  author  has  used  modeling  compound  with  success  by 
heating  it  in  warm  water  until  it  is  of  the  consistency  of  soft 
dough  and  placing  it  in  a  warmed  impression  cup  in  such  a 
manner  that  it  will  cover  all  parts  of  the  teeth  and  jaws 
when  it  is  forced  into  place.  The  impression  cup  should  be 
held  firmly  in  place  fora  moment,  and  a  towel  >aturated  with 
cold  water  should  be  carried  to  all  parts  of  the  mouth  to 
chill  the  compound.  S.  S.  White's  upper  and  lower  impr 
sion  cups.  Xo.  17  and  18,  such  as  are  illustrated  in  Figs.  38 
and  39,  should  be  used  in  taking  impressions  in  cases  of 
irregularities. 

It  is  a  good  plan  to  oil  the  surface  of  the  impression,  thus 
preventing  the  compound  sticking  to  the  cast. 


PART   II TREATMENT. 


85 


To  obtain  the  model,  place  a  sufficient  quantity  of  water  in 
a  bowl  and  pour  in  plaster,  allowing  it  to  settle,  and  thus 
preventing  the  formation  of  air  bubbles  ;  add  enough  plaster 
to  make  it  of  the  consistency  of  cream.  Put  a  drop  of  water 
into  each  depression  made  by  the  teeth  in  the  impression,  to 
exclude  the  air,  and  add  a  small  additional  quantity  of  plas- 
ter. By  tapping  the  cup  upon  the  bench  the  plaster  will 
fill  up  the  depressions  without  the  formation  of  air  bubbles ; 


FIG. 


the  surface  should  now  be  covered  with  plaster,  and  after 
mixing  in  more  dry  plaster  to  make  it  thicken,  fill  the 
impression  full  and  place  it  upside  down  on  a  glass  slide. 
Now  build  out  the  model  until  even  with  the  impression  cup, 
and  allow  it  to  harden.  It  is  better  to  let  it  stand  from 
twelve  to  twenty -four  hours,  that  it  may  become  thoroughly- 
hardened  before  being  removed. 


86 


IRREGULARITIES   OF   THE   TEETH. 


Having  ivm<»vr<l  the  impression,  (rim  (lie  model  roughly, 
ami  after  articulating,  trim  it  so  that  the  body  of  the  model 
will  he  parallel  with  the  line  of  the  teeth,  and  made  present- 
able, for  inspection.  Place  the  name  of  the  patient  and  the 
date  of  the  time  tl peration  was  begun  on  the  surface  of 


FIG.  40. 


the  lower  model,  and  the  patient's  initials  upon  the  upper 
model,  .-.fter  whi«-h  the  surface  should  be  varnished.  A  band 
of  elastie  nihhrr  will  hold  them  together,or  make  an  articu- 
lation «,f  hra-s  wire,  as  illustrated  in  Fig.  4o.  f,,r  the  purport 


PART   II TREATMENT. 


87 


of  holding  the  models  in  their  proper  positions,  thus  prepar- 
ing them  for  easy  inspection.  The  upper  arms  and  spiral 
are  made  of  one  piece  of  wire,  No.  18,  U.  S.  gauge.  The  lower 
arms  are  made  from  another  piece  of  the  same  wire  passed 
through  the  spiral  and  bent  to  correspond  to  the  upper  arms. 
The  models  are  n.ow  articulated,  and  the  wire  arms  bent  to 
meet  the  upper  and  lower  surfaces.  The  surfaces,  after  being 


Fro.  42. 


FIG.  43. 


saturated  with  water,  should  be  covered  with  plaster  and  the 
arms  united  to  the  model. 

The  -cups  for  taking  impressions  of  the  anterior  teeth, 
illustrated  by  Fig.  41,  and  for  the  molars  and  bicuspids,  Fig. 
42,  together  with  suggestions  for  their  use,  were  devised  by  Dr. 
Win.  P.  Cooke,  of  Boston.  He  prepares  a  sufficient  quantity 
of  wax,  and  after  warming  it,  places  it  upon  the  cup.  When 


88  IRREGULARITIES  OF  THE  TEETH. 

„„.  ;,u,  m  in  a  normal  position, and  tlie  saliva  and  mncns 
removed  fmni  theteeth  and  mucous  membrane,  the  cup  wi1 
t!ll.  W.IX  i,  forced  between  thr  li,,s  and  against  the  teeth  am 
cooled  with  a  wet  napkin.    The  patient  is  requested  to  open 
tUemouth  when  the  impression  is  removed,  as  shown  in  I 
,.;     Til(.  I1M),U-l,  Fiji.  44,  is  obtained  by  pouring  plaster  int. 
,„,,,,  U|l,w.r   .,,„!    lower    impressions,  thus   making  a  solid 
I11()(lt.l      Thi*  is  a  very  desirable  way  of  procuring  an  accurate 
.„„!  permanent  model  of  the  mouth  when  one  is  needed  for 
observation  and  study.     It  will  save  time  to  put  tin-in  in  a 
place  runvcnirnt   lor  reference,  which  receptacle  should,  oi 
,.,„!,..,  ,tr  one.     The  modelsshould  be  examined  from 

tin,,,  to  time,  to  note  the  progress  of  the  operation. 


Flo. 


STUDY  OF  THE  MODELS. 

It  is  important  in  regulating  teeth  to  have  a  model  conve- 
niently near  at  hand,  to  be  able  to  improve  spare  moments 
l.y  studying  it,  and  thus  become  thoroughly  acquainted  with 
the  pliysinlogiral  conditions  of  the  teeth  before  attempting 
to  come  to  conclusions  regarding  the  pathology  of  the  case. 
In  determining  the  Character  and  extent  of  a  deformity  some 
criterion  is  necessary.  In  the  human  skull,  taking  the  two 
cuspids  for  our  starting-point,  we  find  that  the  anterior  part  of 
the  average  superior  maxilla  forms  the  arc  of  a  circle,  ami  by 
dropping  a  line  from  the  cusp  of  the  cuspid  to  the  centre  ot 
the  wisdom  tooth,  we  see  that  the  posterior  part  diverges 


PART    II TREATMENT.  89 

considerably  from  the  central  line.     Thus,  Fig.  45  shows  the 
three  normal  lines  of  the  dental  arch. 

The  incisors  of  the  inferior  maxilla  should  close  inside  of 
the  superior  incisors,  and  the  buccal  cusps  of  the  bicuspids 
and  molars  should  occlude  at  the  centre  line  or  sulci  of  the 
superior  bicuspids  and  molars.  If  we  hold  the  articulated 
skull  in  our  hands,  with  the  buccal  surface  toward  us,  we 
will  observe  a  gentle  curve  downward  from  the  cuspid  to 
the  second  bicuspid,  then  rising  until  the  wisdom  teeth  are 
reached ;  thus,  Fig.  46  not  only  shows  the  relative  positions 
of  the  teeth  in  the  jaw,  but  their  relation  to  one  another. 
As  mastication  is  done  principally  by  the  bicuspids  and  first 
molars,  it  is  necessary  that  these  teeth  articulate  perfectly, 
which  is  accomplished  by  the  tooth  of  one  jaw  interlocking 

FIG.  46. 


between   two  teeth   of   the  opposite  jaw,  thus    providing 
support  and  surface. 

If  the  arch  posterior  to  the  cuspids  be  uniform,  and  these 
teeth  are  regular  and  articulate  as  shown  in  the  cut,  they 
should  not  be  interfered  with  for  a  slight  deformity  existing 
in  any  of  the  six  anterior  teeth.  The  cuspids  may  be  spread 
laterally  to  make  all  the  room  necessary.  When  this  is 
accomplished  and  the  deformity  corrected,  all  the  teeth  in 
the  arch  will  adjust  themselves  properly.  If  the  irregularity 
be  complicated,  and  more  room  required  than  can  be  obtained 
by  spreading  the  cuspids,  it  is  best  to  enlarge  both  arches ; 
this  will  give  all  the  space  needed.  To  change  a  well-articu- 
lated set  of  teeth  so  that  the  cusps  of  the  opposite  teeth  will 
strike  would  be  unpardonable. 

7 


90  IRREGULARITIES   OF   THE   TEETH. 

Tin-  arch  of  tin-  superior  and  inferior  maxilla  should  have 
a  diameter  of  sufficient  width  to  prevent  an  impression  of 
the  teeth  on  the  sides  of  the  tongue.  Any  deviation  of  the 
jaw.-  or  teeth  from  this  outline  is  consideVed  a  deformity,  and 
should  receive  the  attention  of  the  dentist. 

|-'.\amininir  the  model  with  this  ideal  in  mind,  we  find 
certain  deformities,  and  the  question  arises  how  to  treat 
them.  Before  proceeding,  we  will  decide,  on  careful  con- 
sideration, that  one  of  two  conditions  exists:  either  the  teeth 
are  in  a  crowded  and  irregular  condition  inside  of  the 
proper  line,  or  they  are  isolated  and  irregular  outside  of  the 
line.  In  the  majority  of  cases  the  irregularity  invoh 
the  teeth  anterior  t<>  the  first  permanent  molars.  If  space 
be  wanting,  the  question  will  arise  whether  to  enlarge  the 
arch  by  force,  or  to  extract  one  or  more  teeth,  and  thus  give 
the  required  room.  The  age  of  the  patient  will  to  a  certain 
extent  decide  this  question.  If  the  temporary  teeth  are 
in  the  mouth,  causing  irregularities,  they  must  he  removed. 
When  the  removal  of  the  second  teeth  becomes  a  necessity, 
a  tooth  should  be  selected  which  is  the  least  prominent  or 
which  will  least  affect  the  expression.  A  good  rule  i-  to 
retain,  it'  possible,  the  six  anterior  teeth.  As  the  cuspids  are 
the  most  prominent  and  give  expression  to  the  face,  they 
should  never  be  removed ;  but  if  one  must  be  sacrificed,  the 
selection  lies  between  the  first  or  second  bicuspid  and  the 
first  molar. 

If  we  find  on  examination  that  the  teeth  are  decayed  (at 
the  a  ire  of  twelve  or  thirteen  years  it  is  common  to  find  the 
lir-t  permanent  molar  decayed),  those  affected  should  he 
extracted  if  the  crowns  are  wholly  or  partially  destroyed.  In 
the  model  of  the  upper  teeth  of  a  girl  fourteen  year-  of  . 
(Fig.  47),  the  bicuspids  are  seen  to  have  advanced  -o  far 
forward  that  there  is  insufficient  space  for  the  cuspid  to  come 
down  into  place.  Upon  examination  of  this  case  it  wa- 
foimd  that  the  first  bicuspid  upon  the  left  side  and  the  first 
•nanent  molar  upon  the  right  side  were  badly  decayed. 
It  was  easy  to  decide  which  teeth  should  be  sacrificed.  The 


PART   II — TREATMENT.  91 

cuspid  upon  the  left  side  came  into  place  without  assistance. 
The  bicuspids  upon  the  right  side  were  carried  back  and  the 
right  cuspid  came  into  place.  It  is  probable  that  in  the  past 
the  first  permanent  molar  has  often  been  extracted  without 
sufficient  cause.  As  this  tooth  serves  an  important  purpose 
in  mastication  on  account  of  its  broad  surface,  I  should 
advise  its  retention  if  the  crown  be  in  a  fair  state  of  preserr 
vation.  It  has  served  for  six  years,  which  fact,  in  connec- 
tion with  its  solidity  in  the  jaws  and  its  central  position,  is 
an  argument  in  favor  of  keeping  it  as  long  as  possible. 

Upon  examining  the  models  of  the  jaws,  we  occasionally 
find  the  articulation  posterior  to  the  cuspids  perfect,  with  the 


Flfi.  47. 


cuspids  nearly  approximating  the  centrals,  and  the  laterals 
locked  inside  of  the  arch.  Whether  they  are  sound  or 
decayed,  it  may  be  best  in  such  cases  to  remove  one  or  both 
laterals.  The  general  appearance  of  the  teeth  will  not  be 
injured  by  this  treatment.  Dr.  Guilford,  in  the  "American 
System  of  Dentistry,"  mentions  two  cases  of  this  kind,  as 
follows  :  "  The  writer  had  two  cases  in  one  year  presented  to 
him  for  the  reduction  of  prominence  in  the  superior  front 
teeth.  In  each  case  there  was  a  broken  or  badly-diseased 
right  central  that  was  past  hope  of  redemption.  In  these 
cases  it  did  not  happen  particularly  amiss,  for  the  extraction 
of  the  roots  afforded  room  for  drawing  in  the  remaining  five 


92  IRREODLARITfES  OF  THE  TEETH. 

teeth,  thus  easily  mincing  the  deformity,  and  at  tin-  same 
time  do-ing  the  -pace  made  by  %t  heir  loss.  Tin-  appearance 
(,f  tin-  patient  in  each  instance  was  greatly  improved,  and 
the  al-ence  of  even  so  large  a  tooth  as  the  rent  ml  was 
(scarcely  noticeable. 

"  In  a  n«>t  her  case,  a  girl  eleven  years  of  age  had  lost  a  right 
superior  central  incisor  through  a  fall  from  a  swing.  Two 
.lav-  alter  the  accident,  and  when  the  tooth  had  been  mislaid 
or  thrown  away,  she  was  brought  for  treatment,  Only  two 
methods  of  remedying  the  difficulty  suggested  them>elves. 
One  was  the  wearing  of  an  artificial  tooth,  the  other  drawing 
thet.eth  together  to  close  the  space.  The  latter  plan  was 
decided  upon,  and  successfully  carried  into  effect, but.  unfor- 
tunately,as  there  had  IHVH  no  protrusion  formerly, and  there 
Mitraction  afterward,  the  superior  teeth  no  longer  over- 
lapped the  lower  ones,  but  met  them  edge  to  edge,  thus  giv- 
ing the  upper  jaw  a  flattened  appearance  which  was  in  itself 
a  deformity.  The  patient  was  saved  the  annoyance  of  wear- 
ing an  artificial  tooth,  but  her  facial  expression  was  injured 
in  consequence." 

Irregularities  of  the  inferior  incisors  are  often  seen,  and  if 
the  articulation  be  normal  in  the  posterior  part  of  the  mouth, 
almost  any  of  the  incisors  that  are  out  of  position  may 
be  removed.  They  resemble  one  another  so  closely  in  size 
and  shape  and  are  so  nearly  concealed  by  the  lip  that  their 
loss  will  not  be  observed.  The  author  would  suggest  that 
tin-  operator  needs  to  be  particularly  careful  in  deciding  upon 
the  mode  of  treatment,  as  he  has  seen  three  ca-es  in  which 
an  actual  increase  of  thedeformity  was  produced  by  a  hurried 
operation.  In  one  of  these,  a  girl  ten  years  of  age,  a  central 
inri.-nr  was  remove.  1.  and  the  muscles  of  the  lip.  together 
with  lateral  pressure  of  the  adjoining  teeth  pu>hrd  against 
the  cu-pids,  forced  the  incisors  into  a  crowded  condition, 
pro-luring  a  V-shaped  arch.  It  was  ascertained  that 
the  articulation  of  the  posterior  teeth  was  not  perfect.  It  has 
been  advi-e.l  |,v  som,.  authorities  to  remove  a  corresponding 
tooth  on  the  opposite  side  where  want  of  room  compels  the 


PART   II TREATMENT.  93 

removal  of  a  tooth  in  the  anterior  part  of  the  mouth.  Thev 
claim  that  there  is  danger  of  the  incisor  moving  by  the 
median  line  when  a  tooth  from  one  side  only  is  extracted; 
but  we  have  found  that  when  a  tooth  is  removed  back  of  the 
canine,  it  is  seldom  that  the  lateral  pressure  is  sufficient  to 
materially  move  the  incisors. 

In  considering  the  bicuspids,  the  one  which  is  the  most 
decayed  should  be  removed.  If  both  are  sound  and  it 
becomes  necessary  to  extract  one,  then  the  first  should  be 
chosen.  In  studying  a  model,  the  end  to  be  kept  in  view  is 
the  retention  of  the  teeth  in  place  after  they  have  found  their 
new  position.  It  is  very  important  that  the  occlusion  of  the 
bicuspids  and  molars  should  be  such  that  when  in  position 
and  properly  articulated,  they  will  hold  one  another  in  place. 
If  this  be  not  accomplished,  the  incline  of  the  cusps  will  force 
the  teeth  into  their  original  faulty  positions. 

APPLICATION  OF  FORCE. 

In  every  appliance  for  regulating  the  teeth  the  object  is 
the  same,  viz.,  to  exert  pressure  upon  the  teeth  to  be  moved. 
Any  appliance  for  this  purpose  should  be  as  small  as  is  com- 
patible with  effectiveness  and  strength.  When  possible,  it 
should  be  so  constructed  that  it  can  be  applied  inside  of  the 
arch  in  such  a  manner  that  it  will  not  interfere  with  speech 
or  mastication,  and  can  be  removed  by  the  wearer  for 
cleansing. 

It  should  give  as  little  annoyance  and  pain  as  possible,  and 
should  not  necessitate  frequent  visits  to  the  dentist  for  its 
adjustment.  Whether  the  teeth  are  to  be  forced  out  or  drawn 
in,  there  are  always  to  be  considered  a  body  to  be  moved 
(the  tooth)  and  a  fixed  point  of  resistance.  By  studying  the 
model  carefully,  the  operator  can  determine  the  amount  of 
force  required  to  move  the  tooth,  and  select  for  the  anchor- 
age of  the  appliance  a  suitable  point  opposite,  which  will 
more  than  resist  the  force  required  to  move  the  tooth.  This 
point  may  be  one  or  more  of  the  natural  teeth,  or  a  plate 
may  be  constructed  for  the  purpose.  In  applying  the  appa- 


94  IKllKOULARITIES   OF  THE   TEETH. 

ratu- 1..  n  t.M.th.  its  portion  in  the  jaw  should  be  observed,  and 
tin-  inclination  of  tin'  root  or  roots  must  be  ascertain! -.1  to 
,1,.,-i.U-  whether  they  stand  perpendicularly  in  the  alveolar 

Boron  an  incline.  All  obstructions  should  be  removal 
by  extraction  (.r  by  lateral  pressure. 

The  I'm •<•!•  should  be  applied  to  the  tooth  to  be  moved 
either  at  right  angles  to  the  long  axis  of  the  root  (Fig.  Is. 
a  b  r).  or  at  an  angle  of  45  degrees,  d  b  c.  By  these  means  the 
tooth  is  prevented  Irom  rising  from  the  socket.  The  position 
of  the  tooth  in  the  jaw,  the  density  of  the  alveolar  j.r 
the  length  of  the  roots,  their  normal  or  abnormal  condi- 

and  length  of  crowns,  will  all  require  consideration  in 


Fi«f  4*. 


deciding  the  amount  and  direction  of  the  force  which  may 
be  used  without  elongating  the  tooth. 

If  the  superior  maxillary  bone  be  examined  after  the  teeth 
are  removed,  it  will  be  seen  that  the  outer  plate  of  the  alve- 
olar process  of  the  superior  maxilla  is  much  thinner  than 
the  inn.  r  plate,  which  is  backed  up  by  the  strong,  thick  hone 
of  the  hard  palate  (Fig.  49),  while  upon  the  inferior  maxilla 
the  outer  plate  of  Ixme  is  thinner  as  far  back  as  the  second 
bicuspids,  and  the  inner  plate  is  thinner  at  the  part  occupied 
by  the  molars.  The  inner  plate  is  thickest  between  the 
.-econd  bicuspids  upon  either  side,  and  is  reinforced  by  the 
symphysis  and  genial  tubercles.  The  external  plate  is 
thickest  in  spaces  occupied  by  the  molars,  and  is  backed  by 


PART    II TREATMENT.  95 

the  external  oblique  ridge  (Fig.  50).  When  the  soft  tissues 
have  been  removed  from  the  superior  maxilla,  it  is  not 
uncommon  to  find  the  roots  of  sound,  healthy  teeth  extend- 
ing through  the  outer  plate  of  bone.  After  the  teeth  have 
been  extracted,  absorption  of  the  outer  plate  takes  place  much 
more  rapidly  than  of  the  inner  plate.  Absorption  of  the 
external  and  internal  plates  of  the  inferior  maxilla  goes  on 
more  uniformly  than  in  those  of  the  superior,  owing  to  a 
more  even  distribution  of  bone. 

In  the  application  of  force,  it  will  be  observed  that  the 


Fio.  50. 


most  pressure  is  required  in  the  direction  of  the  greatest 
resistance,  and  care  must  be  exercised  in  directing  the  force 
toward  the  weaker  parts  of  the  alveolar  process.  The  force 
should  be  uniform  and  steady,  and  enough  to  produce  absorp- 
tion of  bone  without  causing  inflammation,  although  in 
some  cases  slight  inflammation  is  desired.  Here  we  wrould 
discountenance  the  too  rapid  movement  of  teeth,  especially 
when  persons  are  over  twenty  years  of  age.  I  have  seen 
the  alveolar  process  absorbed  to  such  an  extent  that  it  was 
impossible  to  retain  the  teeth  in  their  proper  places,  as  new 


9C  IIlKE(;fLARITIES   OF   THE   TEETH. 

material  wits  not  deposited.  I  would  protest  decidedly 
a'_rain-t  the  drilling  of  holes  in  natural  teeth  for  anchorage, 
practiced  hy  some  reputable  dentists.  There  are  few 
oases  that  cannot  be  treated  by  securing  a  hand  or  cap  ot' 
thin  gold  or  platinum  to  the  teeth  with  oxyphosphate  of 
/inc.  in  which  holes  may  be  drilled  or  hooks  or  loops 
soldered  at  any  required  point. 


CHAPTER  III. 

MECHANICAL  FORCES. 

In  correcting  the  irregularities  of  the  teeth,  the  thoroughly 
educated  dentist  will  have  an  opportunity  to  put  in  practice 
his  knowledge  of  the  laws  of  mechanics.  These  laws  are 
founded  upon  the  action  of  simple  elements  which  are  inter- 
posed between  the  moving  power  and  the  resistance,  for  the 
purpose  of  changing  the  direction  of  the  force.  These  are 
called  mechanical  powers,  and  are  divided  into  two  primary 
elements — the  lever  and  the  inclined  plane.  The  principle 
of  the  lever  is  the  basis  of  the  pulley,  the  wheel  and  axle. 
That  of  the  inclined  plane  is  the  basis  of  the  wedge  and 
screw.  /"Elasticity,  as  shown  in  India-rubber  and  the  spring 
of  metals,  although  not  classified  with  the  primary  forces  in 
mechanics,  plays  an  important  part  in  the  application  of 
force  in  regulating  teeth.  ^  When  these  laws  and  their  appli- 
cations are  firmly  fixed  in  the  mind  of  the  operator,  he  can 
readily  take  advantage  of  the  one  which  should  properly 
be  applied,  or,  when  necessary  to  apply  more  than  one,  can 
combine  them  in  such  a  manner  as  will  best  accomplish 
the  desired  result.  The  degree  and  line  of  force  required 
have  much  to  do  with  the  form  of  appliances  which  should 
property  be  used. 

THE  LEVER. 

The  lever  consists  of  a  rigid  rod,  which  may  be  either 
straight  or  curved,  upheld  by  a  prop  or  fulcrum,  with  the 
resistance  and  the  power  to  overcome  it  at  opposite  ends. 
There  are  three  kinds  of  levers :  1st,  where  the  fulcrum  is 
placed  between  the  resistance  and  power,  as  in  the  see-saw ; 
2d,  where  the  resistance  is  placed  between  the  power  and 
the  fulcrum,  as  in  the  wheelbarrow,  and,  3d,  where  the 
power  is  between  the  resistance  and  the  fulcrum,  as  in  a 
fishing  rod.  Where  the  leverage  can  be  multiplied,  the 

97 


M 


IRREGULARITIES   OF   THE   TEETH. 


mo-t  -tuMxini  M86B  ;ire  obliged  to  succumb,  as  is  illn-trated 
in  rotating  teeth  set  very  firmly  in  the  jaw,  or  thus,  which 
are  crowded  closely,  or  teeth  of  per-ons  in  advanced  years, 
where  the  alveolar  process  has  heeonie  very  dense  and  hard. 
The  increase  of  power  in  the  lever  is  obtained  l>y  length- 
en injj  the  rod  proportionately  or  in  combining  the  leverage 
with  another  I'm-re. 
Tin-  application  of  an  increased  length  of  rod  is  limited, 

Fio.  51. 


l"f  want  of  space  in  the  mouth;  for  if  above  rather  limited 
litnensions    it    interferes   with    the    tongue   or    lips.     We 
nvanahly  use  the  lever  in  any  case  in  whirl,   the  anterior 
rapenor  teeth  occlude  inside  of  the  inferior  teeth,  if  the 
e  presented  early  enough.    It  is  always  desirable  to  n 
these  teeth  as  soon  after  their  eruption  as  possible,  /  ,., 
""'  Ix'ny  tissue   hecome-s  dense  and  hard       Fig    .11 
this  simple  method. 


PART    II — TREATMENT.  99 

The  young  patient  should  visit  the  dentist's  office  early  in 
the  forenoon,  with  the  understanding  that  he  is  to  remain 
all  day.  He  must  remain  where  the  operator  can  see  that 
the  pressure  is  constant.  A  round  piece  of  hard  wood, 
wedge-shaped  at  one  end,  should  be  inserted  between  the 
teeth,  the  point  resting  upon  the  palatal  surface  of  the 
superior  tooth  (which  is  the  body  to  be  removed),  the  stick 
resting  upon  the  lower  incisor  (the  fulcrum),  and  the  force 
applied  by  the  hand  upon  the  lower  end  of  the  lever. 
With  constant  application  of  the  force  the  tooth  will  occlude 
outside  its  opponent  before  the  sitting  is  ended,  and  this 
new  position  will  be  maintained  by  the  pressure  of  the  lower 
teeth  upon  the  upper  until  the  new  position  has  become 
permanent. 

THE  PULLEY,  WHEEL  AND  AXLE. 

The  pulley  is  a  wheel  with  a  groove  cut  into  its  circum- 
ference, and  is  movable  upon  its  axis.  In  mechanics  the 
common  term  for  pulley  is  sheave.  The  pulley  or  sheave 
is  placed  between  the  oblong  blocks  of  wood  through  which 
the  axis  passes  and  supports  the  pulley  in  the  centre.  The 
cord  passing  around  the  pulley  is  called  the  tackle.  The 
bucket  and  weight  in  the  old-fashioned  well  illustrate  the 
pulley.  The  wheel  and  axle  is  a  modification  of  the  pulley. 
The  wheel  is  fastened  securely  to  the  axle,  the  weight  is 
attached  by  a  rope  to  the  axle,  and  the  power  by  a  rope  to 
the  wheel  or  to  handles  fixed  at  right  angles  to  its  rim. 
The  steering-gear  of  a  vessel  is  an  illustration  of  this  kind 
of  lever.  The  forces  combined  in  this  appliance  can  pro- 
duce but  one  result  in  its  application  to  regulating,  viz., 
the  rotation  of  the  teeth  in  their  sockets. 

The  crown  and  root  represent  the  wheel  and  axle,  the 
rubber  band  the  power.  Fig.  52  illustrates  the  rotation  of 
a  tooth  by  having  a  gold  band  with  an  arm  fitted  to  the 
tooth,  and  a  rubber  band  attached  to  the  arm  and  stretched 
to  the  first  bicuspid ;  as  the  tooth  rotates,  the  arm  is  bent  at 
right  angles  to  the  band.  This  application  of  the  wheel 
and  axle  will  accomplish  the  rotation  of  the  teeth  in  the 


100 


IRREGULARITIES   OF  THE   TEETH. 


•  •ises.     The  difficulty  lies  in  the  retention  of 
the   te,-th   aft.T   they    have   Keen    forced    into   their    proper 
,n.     The  younger  the  patient  the  easier  this  will  be 
accomplished. 

To  retain  them  in  place,  an  impression  of  the  teeth  is 
taken  in  modeling  compound,  and  a  model  made  therefrom. 
Bands  of  gold  (Fig.  53)  are  made  to  fit  the  plaster  teeth  with 
flat- and  round-nose  pliers,  and  soldered  upon  their  palatal 
surfaces.  A  piece  of  clasp  gold  is  fitted  to  these  bands  and 
allowed  to  extend  past  the  lateral  incisors;  it  should  then  l»e 
remove<  1  and  soldered,  and  its  edges  filed  perfectly  smooth, 
so  as  not  to  interfere  with  the  tongue.  The  teeth  to  be 


i  •  • 


Fio.  54. 


enclosed  by  the  band  must  be  dried,  and  the  l>and  tilled 
with  o\y  phosphate  of  zinc  and  forced  into  place.  as  in 
fig.  54. 

THE  INCLINED  PLANK. 

The  inclined  plane  is  a  slope  or  flat  surface  inclined  to  the 
hori/oii.  on  which  weights  maybe  raised.  It  is  called  one  of 
the  mechanical  powers,  because  by  it  a  weight  can  In  raised 
up  an  incline  to  a  point  to  which  it  would  be  otherwise 
impossible  to  lift  it.  This  force  is  of  especial  value  in 
in  which  the  nrch  is  to  In-  expanded  by  an  appliance:  under 
Mich  circumstances  the  teeth  exert  an  outward  piv><nre  ..n 
the  opposite  jaw.  and  the  articulation  of  the  ni.-ps  make<  an 


PART    II — TREATMENT.  101 

inclined  plane.  If  the  anterior  superior  teeth  close  inside  of 
the  inferior  teeth,  they  should  be  brought  out  with  the  lever, 
and  if  the  inferior  teeth  are  too  short  to  exert  a  pressure  on 
their  opponents,  they  may  be  fitted  with  a  platinum  cap  and 
cemented  securely  with  the  oxyphosphate  of  zinc.  This 
arrangement  will  maintain  a  constant  outward  pressure  upon 
the  superior  teeth.  Fig.  55  is  another  illustration  of  this 
principle.  In  this  case  a  metal  plate  is  fastened  to  the  teeth 
by  a  ligature  instead  of  an  elastic  band. 


Flu.  55. 


THE  SCREW. 

The  screw,  another  of  the  mechanical  powers,  is  also  a 
modification  of  the  inclined  plane,  and  always  requires  a 
lever  for  the  purpose  of  turning  it.  It  may  be  used  for  pene- 
trating wood,  like  a  thumb-screw,  a  gimlet,  etc.,  or  it  may  be 
used  as  a  moving  force,  as  in  raising  buildings,  or  in  the 
familiar  letter-press.  In  these  cases  it  must  work  in  a  hol- 
low cylinder  with  a  corresponding  thread  cut  inside,  which 
is  called  the  female  screw,  or  nut.  When  the  screw  is  turned 
in  the  nut  it  will  either  advance  or  recede.  This  kind  of 
force  is  of  great  importance  to  the  dentist,  It  is  a  positive 
force,  and  when  properly  applied  it  can  always  be  depended 
upon.  It  is  a  powerful  agent  in  spreading  the  dental  arch, 
obstinate  cases  yielding  readily  to  the  pressure. 


J02  IRREGULARITIES  OF  THE  TEETH. 

If  the  deformity  be  only  on  one  side  of  the  arch,  it  will  !.«• 
necessary  to  obtain  either  a  point  opposite,  by  uniting  three 
or  four  terth  with  hands,  and  thus  giving  a  strong  Mipport, 
or  to  insert  a  rubber  plate  and  vulcani/e  the  nut  int..  place. 
\Vh,-n  the  plate  is  finished,  a  groove  may  be  cut  or  a  hole 
drilled  to  hold  the  screw  in  place.  The  screw  may  be  calh-.l 
a  universal  force,  as  it  can  be  made  to  force  teeth  in  or  out. 
Where  the  roots  are  in  a  diagonal  position  in  tin-  jaw.  «»r  are 
in  dose  proximity  to  their  roots,  the  screw  is  very  eU'ertive. 
re  indebted  to  Dr.  Wm.  H.  Dwinell,  of  New  York,  for 
the  introduction  of  the  jack-screw  as  a  powerful  ami  direct 
force  in  regulating  teeth.  The  following  cuts  illustrate  those 
now  in  the  market  (Fig.  56).  Nos.  1,  2,  3  are  the  original 
fio.34.  jack-screws  introduced  by  I'r. 

Dwinell,  and  are  very  efficient 
when  combined  with  rubber 
plates.  The  screw  is  what  is 
termed  in  mechanics  a  rigl it- 
hand  thread  with  a  single  nut. 
The  distal  end  of  the  screw  is 
made  conical  that  it  may  In- 
directed  either  in  the  plan  IT 
band  around  the  tooth  to  be 
moved.  Holes  should  never  be  drilled  into  sound  teeth  for 
this  purpose.  I  have  invariably  been  successful  in  encircling 
the  tooth  or  teeth  with  a  band  of  gold  or  platinum  retained 
in  place  by  the  oxyphosphate  of  zinc,  and  for  the  purpose 
of  retaining  the  band  and  preventing  the  accumulation  of 
moisture,  have  usually  drilled  a  hole  through  the  band  to 
guide  the  screw. 

4,  5,  6  show  Dr.  A.  MeCullom's  invention,  and  arc 
called  compound  jack-screws.  They  are  made  with  a  right 
and  left  thread,  with  nuts  to  correspond,  so  that  when 
adjusted  they  will  expand  or  contract  if  a  lever  l.e  inserted 
in  the  holes  drilled  through  the  centre  of  the  bar  and  moved 
in  either  direction.  The  length  of  the  bars  may  diilera< -cm-d- 
ing to  the  convenience  of  the  operator. 


PART   II — TREATMENT. 


103 


Fig.  57  represents  a  very  effective  jack-screw  invented  by 
Drs.  Lee  and  Bennett.  It  consists  of  a  screw  and  a  split-post 
nut.  The  plate  must  be  securely  fastened  in  the  mouth,  but 
before  its  insertion  the  post  should  be  vulcanized  into  it.  The 
proximal  end  of  one  of  the  screws  has  a  swivel,  which  is  to 
be  fastened  to  the  tooth  in  order  to  push  it  out  into  line. 
The  other  screw  has  a  cross-head  upon  its  proximal  end, 
with  holes  drilled  through  it  for  the  purpose  of  receiving 
wire  ligatures,  which  have  been  passed  around  the  tooth  to 


FIG.  57. 


be  brought  into  line.     The  screw  should  always  be  used 

in  combination  with  a  plate  or  with  bands ;  otherwise,  the 

teeth  and  gums  are  liable  to  be  injured.    When        FlG.  58. 

the  bicuspids  or  molars  stand  inside  of  the  arch, 

and  a  uniform  pressure  is  required  on   both  | 

sides  of  the  arch,  we  may  prevent  the  nut  from         ^^ 

working  into  the  gum  by  placing  around  the 

teeth  to  be  moved  platinum  bands  with  projectives  soldered 

to  the  edge  nearest  their  cervical  margins  (Fig.  58). 


104  IRREGULARITIES  OF   THE   TEETH. 

THE  WEDGE. 

Tlu-  wedge  is  a  modification  of  the  inclined  plane.  The 
power  is  applied  with  a  hammer  or  a  sledge  to  the  back  of 
tin-  wedge.  It  is  employed  in  various  ways  in  ordinary 
mechanics,  as  in  raising  buildings,  splitting  wood,  etc.  It  is 
an  unsatisfactory  f'»rce  to  calculate  upon,  because  the  large, 
Hat  surfaces  produce  so  much  friction.  On  the  other  hand, 
it>  friction  is  useful  in  retaining  the  wedge  in  its  position. 
Wlu-n  applied  to  the  teeth,  the  wedge  increases  the  diameter 
•  >f  the  arc  of  a  circle  in  which  the  teeth  are  implanted.  It 
i*  usually  made  from  a  fine-grained  wood  orof  India-rubber. 
It  is  a  direct  and  positive  tbive.  and  is  very  effective.  Teeth 
with  long  roots  which  are  set  deep  in  the  alveolar  proce-. 
when  the  latter  is  dense  and  hard,  are  difficult  to  start  with 
ordinary  regulating  appliances.  In  such  cases  the  wedge  is 
of  great  service.  It  will  readily  move  one  or  two  teeth,  and 
not  infrequently  three  will  be  influenced  by  its  piv-suiv. 
Wedge-  made  from  orange  wood  are  found  to  be  very 
viceal.le,  as  they  can  be  readily  reduced  in  si/e  as  the  <•. 
may  ivijuire.  When  applied  to  the  teeth,  they  become  satu- 
rated with  saliva,  swell,  and  in  so  doing  force  the  teeth  apart. 
When  a  rubber  wedge  is  used,  we  select  one  slightly  larger 
than  the  space  between  the  teeth,  and  by  its  elasticity  the 
teeth  are  spread.  The  rubber  wedge  performs  its  work  with 
I«T  rapidity, perhaps,  but  it  causes  more  pain  than  the 
wooden  wedge.  Owing  to  the  elasticity  of  the  rubber,  the 
teeth  vibrate  with  each  effort  of  mastication,  whereas  they 
would  be  held  firmly  by  the  wooden  wedge. 

January  l»th,  1879,  a  woman,  twenty-.-even  years  of  . 
teacher  by  occupation,  came  to  me  for  treatment.  I'pon 
examination  we  found  the  Y-shaped  arch,  dense  and  hard, 
and  removed  the  first  bicuspid  on  the  right  side  and  the 
second  bicuspid  on  the  left  side,  securing  a  silver  plate  to  the 
tiiM  in.ilars.  The  bands  extended  around  the  eu^.ids.  with 
a  nut  and  ><-rew  upon  either  side.  Instead  of  drawing  the 
cuspids  hack  into  the  spaces  made  vacant  by  the  first  bicus- 
pids, as  we  expected  to  do,  the  cuspids  became  the  point  of 


PART   II — TREATMENT.  105 

resistance,  and  the  bicuspids  and  molars  upon  the  right  side 
and  the  molars  on  the  left  side  were  brought  forward  into  the 
spaces.  As  the  incisor  and  cuspid  teeth  were  the  only  point 
of  resistance,  the  molars  being  all  loose,  we  were  puzzled 
how  to  proceed.  We  finally  decided  to  use  the  incisors  for 
the  fixed  point,  and  with  the  compound  force  of  the  screw 
and  wedge  (Fig.  59)  carry  the  anterior  teeth  backward.  A 
rubber  plate  was  fitted  to  the  roof  of  the  mouth  and  about 
the  teeth  that  were  to  remain  stationary ;  the  edge  was 
beveled  where  the  screw  was  applied,  to  prevent  this  being 
forced  against  the  gum.  I  secured  a  jack-screw  of  the  proper 
length  firmly  to  the  cuspid  upon  the  right  side,  allowing  it 

FIG.  59.  FIG.  60. 


to  come  in  contact  with  the  tooth  I  wished  to  move,  the 
bicuspid  of  the  opposite  side  (Fig.  60).  When  this  was  forced 
laterally  sufficiently,  I  removed  the  nut  on  the  end  of  the 
screw,  and  replaced  it  with  a  wedge,  which  was  inserted 
between  the  bicuspid  and  the  cuspid.  The  cuspid  being 
firm,  and  inflammation  having  been  already  produced  around 
the  bicuspid,  it  yielded  readily  to  the  powerful  pressure  of 
the  screw  and  wedge.  When  this  had  proceeded  as  far  as 
possible,  the  wedge  was  removed  and  a  thicker  one  sub- 
stituted. As  soon  as  the  tooth  reached  the  molar  it  was 
secured  to  it  by  ligatures,  and  so  held  in  place.  We  fastened 


106  IRREGULARITIES  OF  THE  TEETH. 

nifimJy  to  the  cuspids  and  forced  them  later- 

v     mil   iMtammt'ion  set  in.     Wedges  were   put    upon 
u.        1  -f  tin-  -n,v.  iK-ing  inserted  between  the  cusp,,  s 
h,  l«.,ml  in"-*.  (Fig.  61).    The  laterals,  being ;  sokc 
a.  ful.-nii.i-,  and  -the  cuspids  were  easily  forced  into 
hliv     The*  were  th.-n  fastened  by  ligatures. 
To  more  tin-  lateral  incisors  a  short  screw  was  employed, 
with  wulp*  in  which  holes  had  been  drilled, 
n-ntral  a  li.n-n  thread  was  tied  and  then  carried  around  the 
|ttll.ml   ow  the  end  of  the  wedge  on  the  screw,  pan 


!  ;    .•:. 


FIG.  62. 


thrmijrh  the  holes  and  tied  fast  (Fig.  62).  By  turning  the 
•crew  the  laterals  were  not  only  forced  outward,  but  were 
rotated  in  their  sockets.  When  this  was  accomplished,  a 
plate  was  fitted  to  retain  the  teeth  in  place  and  also  to  draw 
the  tvntnils  hark  into  the  arch.  This  was  done  by  running 
a  piece  of  gold  wire  across  the  labial  surfaces  of  the  centrals, 
frniu  which  a  rubber  band  was  carried  posteriorly  to  a  loop 
in  tlu-  rubber  plate.  As  soon  as  they  reached  the  proper 
position,  another  plate  was  inserted,  with  a  gold  band  passing 
•f  the  teeth  to  hold  them  in  place. 


PART   II  —  TREATMENT.  107 

ELASTIC  FORCE. 

Each  of  the  six  mechanical  forces  has  its  proper  place  in 


the  art  of  regulating  teeth,  and  when  skillfully  applied 
is  an  effective  agent.  The  application  of  these  forces,  how- 
ever, is  limited.  In  looking  about*  for  effective  powers  wi- 
find  that  the  force  of  elasticity  as  found  in  India-rubber  and 
the  spring  of  metals  combines  all  that  is  necessary  to  render 
effective  either  the  most  rudimentary  or  the  most  intricate 
appliance.  The  simplicity  of  fhe  application  of  this  force 
makes  it  very  desirable  in  dentistry.  Elastic  bands  cut  from 
French  rubber  tubing  can  be  universally  used,  and  are 
applicable  to  every  case  of  irregularity  of  the  teeth.  There 
is  a  power  in  elasticity  peculiarly  adapted  to  the  correction 
of  irregularities,  and  which  cannot  be  obtained  by  any  of  the 
forces  previously  mentioned,  viz.,  a  constant,  equable  pres- 
sure, which  may  be  either  increased  or  diminished  by  the 
application  of  larger  or  smaller  bands.  This  constant  pres- 
sure produces  a  rapid  absorption  of  the  bone  which  opposes 
the  restoration  of  the  tooth  to  its  normal  position. 

When  the  rubber  bands  are  applied  to  the  teeth,  the  point  of 
resistance  becomes  a  very  important  feature.    The  resistance 
must  equal  or  exceed  that  of  the  body  to  be  moved  ;  otherwise. 
the  weaker  will  be  moved  by  the  stronger  force.    If  a  tooth 
upon  one  side  be  irregular,  a  tooth,  or,  if  necessary,  several 
teeth,  at  the  opposite  point  must  be  selected  to  withstand  the 
pressure  of  the  tooth  to  be  moved.     This  not  only  requires  a 
thorough  knowledge  of  the  anatomy  of  the  teeth  and  . 
but  ability  to  judge  the  comparative  resistance  of  each  tc 
We  once  tried  to  draw  by  the  gold  band  and  screw  po< 
right  superior  cuspid  into  the  space  made  vacant  by  t 
of  a  first  bicuspid.     The  point  of  resistance  was  the  >. 
bicuspid  and  the  first  permanent  molar.    It  was  founc 

M  ; 


turning  the  nut  two  or  three  days,  that  the 
molar  had  been  drawn  forward  half  the  space  instead 
ing  the  cuspid  into  the  expected  position 

When  the  rubber  bands  are  employed  in  cases  rec 
much  force,  it  is  generally  a  good  plan  to  fit  a  rubber  Pfc 


I0g  IRREGULARITIES  OF  THE  TEETH. 

othetet-th  and  jaws,  to  which  arms  of  rubber  or  gold  are 
.      -  .„!.• /—  K^«r>  from  rubber  dam, 


model  of  the  teeth  of  a  boy  fourteen  years  of  age. 


Kio.  63. 


Fio.  63. 


!  I 


FIG.  66. 


jaw  occludes  outside  of  the  upper  jaw.     A  plate  with  gold 
band  attachment  (Fig.  64)  was  made  to  fit  the  jaw,  extend- 
ing from  tho  first  bicuspids  around  the  incisors  and  cuspids, 
separated  from  tlu-m  by  a  distance  of  a  <|unrh>r  of  an  inch. 
1-late  was  secured  to  the  first  molars  and  first  lik-uspids. 
Robber-dam  rings  were  fastened  to  the  band  and  carried 
iiu-isors  and  cuspids.     The  teeth  were  in  a  short 


PART  II— TREATMENT.  lflg 

time  brought  out  in  place,  as  illustrated  in  Fi*  65     n, 

between  the  central  incisors.  By  this  means  the  teeth  a" 
readily  brought  mto  their  proper  position,  When  moving 
teeth  or  twistmg  them  in  their  sockets  by  elastic  bands,  it  is 
des,rable  to  start  the  teeth  with  wedges  of  wood  or  rubber 


FIG.  67. 


or  with  the  jack-screw,  to  produce  absorption  of  bone  about 
the  roots  and  make  the  resisting  power  less  complicated  when 
the  bands  are  finally  applied. 

Fig.  67  represents  the  model  of  the  mouth  of  a  woman 
twenty-six  years  of  age.  The  central  incisors  diverge  from 
the  median  line,  and  are  also  twisted  in  their  sockets.  Kul>- 
*ber  bands  were  placed  about  the  teeth  to  draw  them  together. 
The  pressure  required  was  so  great  that  two  bands,  each  one- 
fourth  of  an  inch  wide,  with  a  linen  ligature  tied  with  a  sur- 
geon's knot  on  the  outside  of  the  bands,  were  required.  Even 
with  this  powerful  force  it  took  three  weeks  to  bring  the  teeth 


110  IRREGULARITIES  OP  THE  TEETH. 

-ether.    Having  produced  absorption  of  the  alveolar  pro- 
2TSe  teeth  were  easily  rotated  in  their  sockets  m  the 

"' AMnd  Xtlnum  was  accurately  fitted  to  the  crown  and 
eoldere.1  \  h«H.k  was  made  by  inserting  and  soldering  a 
„  fr,,,,  an  artificial  tooth  into  a  hole  drilled  in  the  labio- 
!li«tul  angle  of  the  band;  this  band  was  fastened  upon  the 
t,H.tli  with  oxyphosphate  of  zinc ;  a  band  of  rubber  was  then 
attached  at  one  end  to  the  hook,  and  at  the  other  to  a  bicus- 
pid, the  tooth  being  thus  rotated  into  place.  Another  plan 
is  to  dry  the  tooth,  coat  it  with  sandarac  varnish,  and  while 
moist  to  wind  about  it  a  strip,  cut  from  rubber  dam,  three- 


Fio.  68. 


sixteenths  of  an  inch  wide  and  two  inches  long,  with  a  string 
tie<l  in  its  middle,  so  that  the  rubber  dam  doubles  upon  itself. 
The  band  should  be  wound  in  the  same  direction  in  which 
tin-  tooth  is  to  be  rotated,  and  the  winding  should  be  con- 
tinued until  the  end  of  the  rubber  reaches  the  distal  edge  of 
the  tooth ;  the  string  should  now  be  drawn  across  the  mouth 
and  tied  to  a  molar  or  bicuspid  tooth.  Either  of  these 
arrangements  is  very  effective. 

The  trying  part  of  these  operations  is  to  retain  the  teeth 
after  tlu-y  have  been  brought  into  place.  The  following 
method  can  be  relied  upon  for  this  purpose:  A  band  of  gold 


PART   II — TREATMENT. 


Ill 


or  platinum,  made  to  fit  the  teeth,  is  placed  on  a  model,  to 
which  is  attached  a  bar  extending  beyond  the  lateral  incisors 
(Fig.  68).  This  is  fastened  to  the  teeth,  after  they  have  been 
dried,  with  oxyphosphate  of  zinc.  This  band  must  remain 
on  the  teeth  for  from  six  months  to  two  years,  when  a  deposit 
of  bone  will  have  formed  which  will  in  most  cases  hold  the 
teeth  in  place. 

LIGATURES. 

Ligatures  are  cords,  strings,  or 
wires  for  binding  the  teeth  while 
regulating,  for  the  attachment  of 
other  appliances  to  the  teeth,  or  for 
holding  them  securely  after  they 
have  found  their  places.  Silk,  linen 
or  Chinese  grass  ligatures  serve  a 
good   purpose,  but  the   ordinary 
silk  twist  found  in  dry-goods  stores 
does  the  work    better  than  any 
other    ligature.     When    ligatures 
are  used  to  regulate,  they  act  upon 
the  teeth  to  be  moved  by  attach- 
ing them   to  a  fixed  point,  and 
also  by  the  shrinkage  of  the  fibre 
when    moistened.       Care    should 
be  taken  in  tying  the  knot  of  a 
ligature  to  avoid  its  working  up 
under  the  gum.    Various  knots 
can  be  made  for  this  purpose.  Jig. 
69  shows  some  good  ones.    Since 
the   introduction  of  Dr.   Magill's 
band  for  regulating  teeth,  the  liga- 
ture has  become  a  very  useful  ad- 
junct for  fastening  appliances  at 
any  point  upon  the  band  where  a 
pin  has  been  previously  soldered  to  it. 


HO  IRREGULARITIES  OF  THE  TEETH. 

THE  ELASTICITY  OF  METALS. 

The  molecules  of  me*tals  are  held  together  by  a  force 
called  cohesion.  These  particles  change  in  their  relative 
position"  \vlifn  the  metal  is  acted  upon  by  an  external  force. 
If  this  t<.r« «  1*  removed  before  these  changes  exceed  a  certain 
limit,  tin-  particles  return  to  their  previous  positions.  This 
iN.wrr  of  returning  to  original  form  is  called  elasticity.  This 
elasticity  of  metals  may  be  utilized,  in  regulating  teeth,  with 
powerful  results,  which  are  only  limited  by  the  amount  of 
spring  which  a  metal  possesses.  Metals  are  classified  as  per- 
fectly elastic  and  inelastic,  which  terms  imply  that  there  are 
many  .leaves  of  elasticity  between  the  two  extremes.  It  is 
now  claimed  that  a  metal  cannot  be  perfectly  elastic;  that  is, 
it  cannot  go  back  exactly  to  its  previous  form.  It  is  also 
claimed  that  every  body  is  elastic  in  a  degree.  Pure  gold 
it* -If  belongs  to  the  inelastics;  when  alloyed  with  other 
metals,  e.  g.,  platinum,  it  is  a  perfectly  elastic  metal.  Some 
members  of  the  dental  profession^have  utilized  this  force  for 
regulating  with  great  success. 


CHAPTER  IV. 

CONSIDERATION  OF  DIFFERENT  METHODS. 

THE  PATRrCK  METHOD. 

The  system  of  regulating  devised  by  Dr.  J.  R.  Patrick,  of 
Belleville,  111,  is  unlike  any  of  its  predecessors.  It  is  taed 
upon  the  elasticity  or  spring  of  a  bow-spring  wire  of  platin- 
ized gold,  which  is  anchored  by  suitable  bands  to  teeth 
elected  for  this  purpose.  The  wire  is  half  round  and  of  a 
standard  size ;  the  bands  for  anchorage  are  attached  to  suit- 
able slides,  fitting  the  wire  accurately,  so  that  they  can  be  at 


FIG.  70. 


once  adjusted  to  the  teeth  selected.  The  force  of  the  bow- 
spring  wire  is  applied  to  the  teeth  which  it  is  desired  to 
move  by  means  of  wedges,  hooks,  T-bars  and  catches,  of 
shapes  and  sizes  as  desired,  which  are  attached  to  similar 
slides,  all  fitting  the  bow-spring  wire,  so  that  any  desired 
number  or  forms  of  appliances  can  be  readily  adjusted  at  the 
same  time. 

Figure  70  represents  the  bar  or  wire,  which  is  bent  so  as 
to  conform  to  the  buccal  surfaces  of  the  teeth ;  and  the  dif- 
ferent attachments  are  also  shown.  In  use,  the  anchor  bands 
are  properly  adjusted  and  retained  in  position  by  set-screws 
passing  through  them,  and  provided  with  a  head  or  button 

113 


]14  IRREGULARITIES   OF  THE   TEETH. 

f,,r  turning  thorn,  as  shown.  The  wire  rests  upon  the  buccal 
,urfan-  of  tin-  molars  to  which  it  is  attached,  and  the  hooks, 
wedges  or  other  appliances  are  brought  to  the  positions 

faired. 

Any  tend.-ncy  of  the  anchor  bands  to  change  their  posi- 
tion u].on  tin-  teeth  may  be  obviated  by  lining  them  before 
adjustment  with  thin  oxy phosphate  of  zinc.  If  the  bar 
incline  t<>  slip  upward  toward  the  gingival  margin,  this  inay 
U»  ol.viated  hy  an  attachment  in  the  shape  of  a  small  hook 
reMinj;  upon  one  of  the  teeth. 

The  apparatus  acts  as  a  lever,  the  power  being  the  elastic- 
ity <>f  tin-  bow  spring,  the  fulcrum,  the  teeth  used  for  anchor- 
age, and  the  resistance  the  tooth  or  teeth  to  be  moved. 
Kul.U-r  Lands  may  also  be  used  as  auxiliaries. 

This  appliance  is  ingenious  and  possesses  many  advan- 
tages. It  is  claimed  by  the  inventor  that  any  form  of  irregu- 
larity can  be  successfully  treated  with  it.  Only  one  band  is 
needed,  and  no  impression  of  the  mouth  is  required;  being 
conijK»sed  entirely  of  incorruptible  metal,  it  is  easily  and 
thoroughly  cleansed,  and  without  removal  from  the  mouth. 
It  can  also  be  adjusted  or  tightened  at  any  time  without 
removal.  It  can  he  applied  to  either  jaw  with  equal  facility. 

The  principal  objection  urged  against  this  appliance  is 
that  the  teeth  used  as  fulcrums  or  attachments  are  some- 
times not  sufficiently  firm  to  resist  the  pressure  they  are 
required  to  sustain,  and  in  that  case  will  move  before  the 
tooth  which  is  being  operated  upon.  This  could  probably 
be  obviated  by  attaching  to  more  teeth. 

The  construction  must,  of  necessity,  be  accurate,  and  if 
made  by  the  dentist,  requires  great  nicety  of  workmanship. 
Hut  all  difficulties  of  this  nature  are  banished  by  the  fact 
that  it  can  be  obtained  at  the  dental  depots. 

THE  FARRAR  METHOD. 

the  distinctive  systems  of  apparatus  for  regulating  the 

:hat  devised  by  Dr.  J.  X.  Farrar,  of  New  York,  was 

ong  the  first  to  be  presented  to  the  profession.     It  was 


PART   II — TREATMENT. 


115 


introduced  by  him  about  1876.  The  principle  upon  which 
it  operates  is  peculiar  to  the  system,  which  is  called  by  the 
inventor  «  The  Positive  System."  In  all  (or  most)  methods 
employed  previously,  the  endeavor  was  to  bring  to  bear 
upon  the  tooth  or  teeth  to  be  moved  a  force  that  should  be, 
so  far  as  possible,  continuous.  Wedges,  rubber  bands,  springs^ 
etc.,  even  the  inclined  plane,  are  all  examples  of  this  con- 
tinuous force,  which  it  is  the  endeavor  to  continue,  in  greater 
or  less  degree,  from  the  beginning  to  the  end  of  the  operation. 
Dr.  Farrar's  system  is  peculiar  in  this,  that  he  uses  only 


FIG.  71. 


the  screw  as  a  power,  which  he  considers  to  be  the  only 
force  capable  of  being  applied  with  a  definite  and  positive 
result.  His  theory  is  that  a  tooth  should  be  moved  a  certain 
distance,  as  far  as  it  is  safe  or  proper,  at  one  push  or  thrust, 
and  then  retained  immovable  in  that  position  for  a  certain 
length  of  time.  By  this  means  he  claims  that  the  tissues  in 
front  of  the  advancing  tooth  are  compressed,  and  kept  com- 
pressed to  such  a  degree  that  absorption  takes  place  readily 
and  without  inflammation,  thus  making  place  for  the  toot 
being  moved,  while  at  the  same  time  a  deposition  of 


116  IRREGULARITIES  OF  THE  TEETH. 

takes  place  bthind  the  tooth,  tending  to  retain  it  in  its  new 

position     This,  then,  is  the  principle  of  the  Farrar  method  : 

a  pwitivr  thrust  to  a  known  and  definite  extent,  the  tooth 

_•  retained  hy  tin-  appliance  in  the  new  position,  and  a 

,.i  ,,f  |H  rfect  rest  allowed  to  intervene  before  more  force 

l-  applied. 

The  apparatus  by  which  the  results  are  accomplished  is 
constructed  of  ls-carat  gold.  An  illustration  of  this  appli- 
ance is  shown  in  Fig.  71. 

In  all  (»f  his  appliances  a  screw  is  to  be  found,  upon  which 
tin-  thn-ads  an-  cut — sixty  to  the  inch.  The  end  of  the  screw 
is  fittnl  t<.  IK-  turned  with  a  watch  key  (Fig.  72) ;  one-half 
a  turn  twin-  a  day  will  move  the  tooth  y^  of  an  inch  a  day, 
which  rate  of  progress  Dr.  Farrar  finds,  by  experiment,  to  be 
about  th»-  maximum  rapidity  consistent  with  safety  ;  and  he 


Flo.  72. 


claims  that  this  will  produce  only  a  slight  uneasiness  or 
sense  of  tightness,  and  no  pain.  He  also  claims  that 
patients  may  be  easily  instructed  to  turn  the  screw  them- 
selves, and  to  regulate  the  pressure  by  the  sense  of  tight- 
ness, thus  saving  many  visits  to  the  office  and  the  time  of 
the  operator. 

THE  BYRNES  METHOD. 

v  Byrnes,  of  Memphis,  has  devised  a  method  of 

whieh  is  worthy  of  notice.*     He  uses  thin  gold 

D  or  22  carats  fine,  the  motive  power  being  the 

force  of  the  bands.    No  plates  are  used,  the 

tong  obtained  upon  such  of  the  teeth  as  are 

fixed  points  having  been  determined,  the 

ited  are  connected  to  them  by  means  of  a 

*  *>t»tal  Coanos,  May,  1886. 


PART   II — TREATMENT. 


117 


thin  gold  band.  This  is  so  manipulated  as  to  form  a 
spring  or  series  of  springs,  so  adjusted  as  to  bear  most  pow- 
erfully on  the  misplaced  tooth  or  teeth.  For  instance,  in 
the  case  of  a  misplaced  incisor,  to  be  drawn  inward,  a  con- 
tinuous band  embracing  the  first  molars  on  each  side  is 
fitted  around  the  outside  of  the  arch.  With  a  dull-pointed 
instrument  like  a  burnisher,  the  ribbon  is  then  pressed  into 
the  interstices  of  the  teeth  over  which  it  passes,  thus  forming 
it  into  a  series  of  small  springs.  The  incisor,  being  the  most 
prominent  point,  will  naturally  be  most  affected  by  the 
pressure  exerted  by  the  springs,  and  in  a  short  time  it  will 
be  found  to  have  moved  away  from  the  band,  so  that  it  is  no 


longer  affected  by  the  tension  of  the  springs.    The  apparatus 
is  then  removed,  the  ribbon  is  annealed,  straightened,  anc 
small   piece  cut  out  of  it;  the  ends  are  soldered  and 
replaced,  and  the  band  formed  into  a  spring  as  befc 
This  method  is  stated  to  be  equally  applicable  \ 
simple  and  complex  conditions     Sometimes 
the  band  may  be  advantageously  supplement,,! 
aids,  as  the  insertion  of  a  rubber  wedge  a  part u-u 

r^T^r^s^;  r; 

SraSsss.Tjsr.tt 


H8  ^REGULARITIES  OF  THE  TEETH. 

behind  the  band  opposite  to  one  of  the  int^ 
rice?    ,h,.n  being  fetched,  it  can  be  worked  to  the  desir.,1 
POL  vltrn  the  enda  should  be  clipped  off 

•«  nitrate,  a  case  treated  and  described  by   Dr. 

Urn*     T!i.-  i«iti.-nt  was  a  young  lady  of  eighteen  yea,-. 

whl>  ha(,  1,,,,  ih,  ri-l.t  superior  central  at  the  age  of  eleven. 

X  vulrinif  plati-  ha.l  IKM-II  xv..rn  fi.r  three  and  a  half  years. 

Th-  remaining  upin-r  anterior  teeth  had  been  forced  out- 

:  until  ,lu.v  st.KHl  at  an  angle  of  forty-five  degrees  when 

.,,-n     The  lower  incisors  stood  inside  the  arch,  and  the 

Chin  WM  cunM^uently  wrinkled  and  upturned.     The  lips 

,nt    ix)ut,  the  mouth    being  what  is  termed 

peaked,  the    molars  being  the  only  teeth   that  occluded 

rly. 


Ki...  74- 


In  treating  this  case,  it  was  the  object,  1st,  to  correct  the 
"  peakedness  "  by  producing  a  broader  and  more  oval  arch  ; 
K-  n-«liirtiiiii  ..f  tlie  projecting  teeth;  3d,  the  improve- 
ment «.f  (li«.  articulation,  and  4th,  the  closure  of  the  spacv 
caused  by  the  loss  of  the  central.     The  last  was  undertaken 
firet    A  ht-avy  Land  (Fig.  74)  was  used  to  force  the  cutting 
edges  of  the  right  central  and  left  lateral  together.     A  very 
thin  narrow  jr,,M  l,;m.l  was  then  fitted  to  eml.nuv  the  neeks 
these  Urth.  and  a  wedge  of  wood  was  inserted  on  the  side 
tlit-  .-uttina  c(iges>  causing  the  teeth  to  move  vertically 
rard  each  oth,  r.    Another  band  (Fig.  75)  was  then  con- 
to  move  the  incisors  backward,  and  was  placed 
ition  without  removing  the  first.     It  embraced  the 


PAET   II — TREATMENT.  119 

cuspids  and  bicuspids  on  each  side;  the  connecting  band 
was  pressed  into  the  interstices,  and  rubber  wedges  inserted. 
The  effect  of  this  was  not  only  to  cause  backward  pressure 
upon  the  incisors,  but  an  outward  pressure  on  the  cuspids 
and  bicuspids.  At  the  end  of  three  weeks  the  work  un- 
practically accomplished,  and  the  fixture  was  replaced  by 
that  shown  in  Fig.  76,  which  completed  the  movement  of 
the  teeth,  and  acted  as  a  retaining  piece.  The  small  hook 
counteracted  the  tendency  to  slip  up  toward  the  gum. 

The  regulation  of  the  lower  teeth  was  begun  soon  after 
that  of  the  upper  jaw  was  completed,  and  was  carried  through 
in  about  three  weeks.  A  band,  shown  in  Fig.  77,  was  used, 
clasping  the  first  molars,  passing  around  the  bicuspids  and 

FIG  76.  FIG.  77. 


behind  the  incisors.    A  wooden  wedge  was  placed  between 
the  incisors  and  the  band,  and  springs  formed  by  pr< 
the  latter  into  the  interstices  between  the  cuspids  and 
pids      In  two  weeks  this  apparatus  was  replaced  by 
shown  in  Fig.  78.     A  little  block  of  rubber  under  each  c 
the  rings,  which  rested    upon  the  cuspids    complete 
work  in  a  week.     The  rings  being  pressed  back  to  presen 
the  ground  already  gained,  the  piece  was  worn  as  a  * 
plate.     The  final  result  is  shown  in  I 

Fig.  80  illustrates  the  teeth  of  a  lady  aged  t^nn 
The  lower  cuspids  closed  in  front  of  the  upper    theden 
sapientes  were  erupting  into  a  crowded  arch,  and  pu 


110 


IRREGULARITIES  OF  THE  TEETH. 
Fio.  79. 


I  :      -  . 


FIG  81. 


Fio.  82. 


PART  JI — TREATMENT.  ]2l 

the  lower  cuspids  still  further  forward.  The  first  bicuspid* 
were  extracted  to  make  room,  and  the  cuspids  were  n.ovr.l 
backward  by  means  of  a  band,  shown  in  Fig.  81,  which 
embraced  the  first  molar  and  cuspid.  The  molars  \\. -n- 
capped  to  prevent  occlusion,  but  the  age  of  the  patient  pre- 
venting rapid  movement,  the  bands  were  cut  and  tightened 
only  twice  a  week.  In  ten  weeks  the  work  was  completed— 
Fig.  82  showing  the  appearance  at  the  conclusion  of  tin- 
treatment. 

Fig.  83  shows  the  upper  jaw  of  a  lady  aged  twenty-two, 
who  fell  at  the  age  of  ten  years,  striking  the  superior  teeth 
in  such  a  way  as  to  knock  out  the  right  lateral  and  dislocate 
the  other  incisors,  the  left  central  remaining  at  an  angle 
of  thirty -five  degrees  after  its  attachment  was  again  renewed. 
The  incisors  were  separated  from  each  other,  and  the  deform- 
ity much  more  marked  than  shown  by  the  cut. 

Fig.  84  shows  the  appliance  in  position  used  by  Dr.  Byrnes 
in  this  case,  by  which  the  regulation  was  completed  in  eight 
sittings.  The  connecting  band  was  crimped  as  shown,  thus 
converting  it  into  a  series  of  springs.  Fig.  85  was  used  in 
a  case  in  which  the  right  central  overlapped  the  lateral. 
The  springs  were  adjusted  so  as  to  turn  the  tooth,  the  w<»rk 
being  accomplished  in  four  days,  after  which  it  was  retained 
by  a  simple  band,  with  wings  resting  on  the  left  central 
and  under  the  right  lateral. 

THE  COFFIN  METHOD. 

Dr.  Walter  H.  Coffin,  of  England,  read  a  paper  before 
Section  XII  of  the  International  Medical  Congress,  held  at 
London,  in  August,  1881,  upon  "A  Generalized  Treatn.en 
of  Irregularities."     Upon  that  occasion  he  gave  tin-  . 
profession  one  of  the  most  valuable  appliances  for  reguli 
ing  teeth  that  has  ever  been  devised.     It  is  called  by  t 
inventor  an  «  expansion  plate."    The  principle  upon  whi 
this  system  of  regulating  is  based  is  quite  different  fron 
other:    It  was  not  new  when  presented  as  above,  h 


I  oo 


IRREGULARITIES  OF  THE  TEETH. 

FIG.  88. 


Fio.  84. 


Fio  83. 


PART   II— TREATMENT.  J23 

been  used  by  Mr.  Coffin  and  his  son  for  a  period  of  twenty. 
five  years.     Since  it  became  known  in  this  country  it  haa 

STliDta  v!^gen^  US6'  and  is  P°Pularl*v  k»°™  as  the 
Coffin  Split  Plate  "  Method. 

The  principle  upon  which  this  method  acts  is  by  the  con- 
struction and  adaptation  of  a  vulcanite  plate,  not  only  cov- 
ering the  hard  palate,  but  capping  the  posterior  teeth ;  the 
plate,  after  vulcanizing  and  finishing,  is  to  be  split  into  two 
halves.  These  halves  are  connected  by  a  piece  of  win- 
bent  into  the  shape  of  the  letter  W  (Fig.  86),  having  th.- 
ends  flattened  and  imbedded  in  the  vulcanite  plate.  This 
wire,  or  spring,  being  suitably  adapted  to  the  cast,  and  bent 
with  the  proper  shape  while  cold,  is  pressed  into  the  wax 


FIG  83.  FIG.  87. 


model  upon  the  cast  until  the  proper  position  is  secured.  To 
prevent  its  displacement  while  packing,  bits  of  binding-wire 
may  be  twisted  around  it  at  various  points,  which  will  hold 
firmly  in  the  plaster.  A  piece  of  heavy  tin-foil  covering  the 
wax  model  on  the  lingual  surface  will  bring  out  the  rubber 
with  a  polished  surface  under  the  wire.  The  piece  having 
been  vulcanized,  is  split  lengthwise  with  a  fine  saw  (Fig. 
87).  The  plate  is  now  introduced  and  properly  fitted, 
secure  accurate  adaptation  to  the  teeth,  a  perfect  impression 
and  a  perfect  model  are  necessary.  The  inventor  recom- 
mended gutta-percha  or  balleta  gum  (modeling  compounc 

The  plate  being  properly  adjusted  in  the  mouth,  is 
without  any  tension  for  a  day  or  two-until  the  patient  I 


,,,  IRREGULARITIES  OF  THE  TEETH. 

mtomed  to  its  presence.    The  two  halves  are 
n  separated  hv  UMIIK  stretched  apart,  by  which  means  the 
n.  i<  converted  into  a  spring  of  great  power  and 
tension.     Any  desired  direction  maybe  given  to 
fon-e.  and  the  pressure  thus  brought  to  bear  where .1 

niOSt  Heeded. 

'I'll.-  primary  effect  of  this  arrangement  is,  of  course,  fc 
:,d  th,-  arch  laterally,  thus  affording  room  for  the  rota- 
tion ..r  removal  «.f  the  irregular  teeth.  In  a  large  majority  of 
cases  such  an  expansion  is  either  absolutely  essential  or 
highly  deMrahle.  and  by  no  other  appliance  can  it  be  so 
readily  obtained.  The  inventor  even  claims  that,  paradoxi 


FIG.  88. 


t-al  though  it  may  seem,  it  is  less  painful  and  troublesome  to 
secure  in  this  way  ample  spaces  between  all  the  front  teeth 
at  once,  than  to  wedge  two  of  them  apart  in  the  ordinary 
with  the  advantage  of  easily  maintaining  their  sepa- 
ration. 

I  hi-  appliance,  as  will  be  readily  seen,  is  designed  for  an 
altered  shape  or  outline  of  the  dental  arch ;  where  this  is  not 
needed,  the  power  of  the  spring,  or  of  a  suitable  spring 
properly  inserted,  may  be  brought  to  bear  upon  any  tooth 
which  it  i.s  desired  to  operate  upon,  so  as  to  produce  rotation 
r  mov.-mmt  in  any  direction.  In  this  case  the  plate  is  not 

it,  hut  wire  is  anchored  into  it  in  a  suitable  position,  its 


PART  II — TREATMENT.  125 

end  protruding  to  bear  upon  the  tooth  it  is  desired  to  move 
Wires  can  be  inserted  so  as  to  operate  on  one  or  two  teeth  at 
the  same  time  (Fig.  87). 

The  same  principle  may  also  be  applied  to  the  regulation 
of  teeth  m  the  lower  jaw.  In  this  case,  the  plate  (Fig.  88) 
is  made  in  a  horseshoe  form,  and  the  wires  lie  along  its 
lingual  aspect  in  a  simple  U-shape  or  semicircle,  the  plate 
being  divided  at  the  median  line. 

By  stretching  the  wire  more  and  more  as  the  case  pro- 
gresses, an  expansion  to  a  very  considerable  extent  may  be 
effected,  and  so  easily  that  caution  must  be  observed  not  to 
exceed  the  intended  results. 

PIANO-WIRE. 

Piano-wire  is  manufactured  in  Germany,  England  ami 
America.     It  is  made  of  the  best  steel,  drawn  through  a  draw- 
plate  to  the  required  size.     The  polish  and  temper  are  given 
during  this  process.     The  wire  must  be  extremely  pliaMe 
and  strong  to  endure  the  tension  which  it  undergoes  during 
the  tuning  process  of  a  piano.     It  must  also  be  perfect  in 
construction,  as  any  flaw  in  the  wire  would  cause  it  to  snap 
when  being  manipulated.    It  has  advantages  over  any  other 
wire  for  dental  purposes.     It  is  inexpensive,  has  greater 
elasticity  than  other  wares,  and  can  be  more  easily  adapted  to 
a  variety  of  cases.     It  can  be  bent  in  any  way  necessary  to 
obtain  the  greatest  amount  of  force,  and  can  be  applied  to 
any  place  in  the  mouth,  on  account  of  its  small  size  and 
weight.     Sizes  18,  19,  20  are  better  suited  to  the  majority  of 
irregularities,  the  strength  of  the  wire  to  perform  a  given 
operation  depending  upon  the  age  and  constitution  of  the 
individual  and  the  character  of  the  irregularity, 
or  in  delicate  organizations,  No.  20  is  the  size  best  a.lapte. 
regulate ;  the  sizes  should  decrease  to  No.  17  as  the  yes 
advance,  or  as  the  stubbornness  of  the  irregularity  dec 
The  selection  of  the  wire,  and  adapting  it  to  each  . 
case  so  as  to  obtain  the  best  results  and  avoid  prc 
inflammation,  will  require  the  nicest  discrimination. 


126  ,RREOULARITIES  OF  THE  TEETH. 

THi:  AITHOK'S  METHOD-THE  COIL 

!„  unler  to  obtain  the  best  results, the  elasticity  of  the  wire 
was  increased  by  coiling  it  from  one  to  three  times  around 

.M11,,,,ln|  The  ;m,hor  has  phuvd  his  coil  springs  at  the 
,,,.„,„!  (l,.p<,,,  for  the  benefit  of  those  who  cannot  take  the 
timt.  t(l  ,11;,ke  their  own  springs.  The  mandril  is  driven 
in!,,(ll(.  h,nch.  and  with  the  right  hand  the  wire  is  coiled 
nUut  it  as  many  times  as  required,  the  short  end  being  held 
firmly  by  the  left  hand.  The  coil  ends  directly  at  the 
>tartin-point.  and  gives  thereby  the  greatest  elasticity  and 
1,-n-th  of  arms.  When  necessary,  the  Ion-  end  of  the  wire 
ran  In-  bent  with  square-nose  pliers  to  make  it  on  the  same 
plane  with  the  other  arm.  Fig.  89  shows  the  coil  spring. 


FIG.  89. 


The  coil  of  the  spring  works  on  the  same  principle  as  the 

mainspring  of  an    American    watch,  which    between    two 

jM.int>  measure^  a  uniform  period  of  time.     The  extremities 

of  the  arms  of  the  spring  travel  over  a  given  space  with  like 

uniformity,  which  gives  a  mild,  uniform  pressure  to  the  jaws 

an«l  uvth.    The  arms  may  be  hent  or  cut  at  any  length  to 

suit  the  cast-  in  hand.     They  may  be  used  in  connection 

with  a  rul.U-r  plate,  or  with    bands  of  gold    or   platinum 

"•'1    t.,  the    teeth   with    oxyphosphate  of   zinc.     With 

properly  drilled  in  the  plate  or  bands,  and  the  arms 

itu-d  into  them,  the  spring  will  stay  in  position.     When  the 

>pring  i,  „,,.,!  without  a  plate,  it  may  be  well  to  fasten  the 

«nre  to  some  of  the  teeth  to  prevent  its  being  swallowed. 


PART  II—  TREATMENT. 


°f  the 


12? 


in 


The  following  models  of  the  mouth  of  a  girl  sixteen  years 
f  age  were  presented  to  the  author  by  Dr.  J.  F.  Austin,  of 


FIO.  no. 


Chicago.  The  right  cuspid  had  encroached  upon  the  lateral 
incisor  to  such  an  extent  as  to  twist  and  force  it  out  of  posi- 
tion, leaving  only  about  one-half  the  space  necessary  to 


FIO.  91. 


rotate  the  tooth  into  place.  A  plate  was  made  to  fit  th.- 
mouth  and  teeth,  and  a  coil  spring  inserted,  with  arm- 
meeting  the  cuspid  and  central  incisor.  The  spring  was 


IRREGULARITIES  OF  THE  TEETH. 

,,,n,l  to  tin-  plate  by  a  pin  driven  into  the  plate  (Fig.  90) 
v  the  lateral  j.n-un-  of  the  spring  the  teeth  were  pushed 

.part,  makin,  *  the  teeth  to  be  rotate,!  into  place 

.howi  the  tooth  secured  in  position  by  the  Magil 

retainer. 

>l'l;i:\I>IN<;  THE  DENTAL  ARCH. 

On  mi  exact  plusti-r  model  of  the  case  to  be  regulated  a 

thin,  narmw  vulcanite  plate  is  formed,  with  a  short  vertical 

poll  fixed, either  before  vulcanizing  or  afterward  by  drilling 

rally  in  tin-  j.late  <»n  the  median  line.     Grooves  or  slots 

witii  a  wheel  bur.  cut  in  the  sides  of  the  plate  to  receive 


Kio.  92. 


the  eii. Is  of  the  spring  and  prevent  its  displacement  after  the 
coil  has  hrrn  plaeed  on  the  post.     Fig.  92  represents  such 
an  appliance  in  position  on  a  plaster  cast  of  the  inferior 
maxilla  of  a  boy  aged  twelve  years,  and  it  will  thus  l.e  seen 
that  tin*  MM'venirnts  of  the  tongue  would  not  be,  as  in  prac- 
tice tli.-y  \vnv  n,,t,  seriously  restricted.     The  tension  of  the 
spring  is  changed  by  simply  bending  outward  or  inward  its 
inns,  and  in  many  cases  the  apparatus  may  be  inserted  or 
removed  with  -rmt  facility,  and  its  action  be  so  continued 
I  contn.lh-d  that   the  required   expansion    may  be  ob- 
'1  and  maintain,-,!  by  the  use  of  but  one  plate.     This 


PART   II — TREATMENT. 


129 


plate,  with  spring  attached,  was  removed  by  the  boy  twice 
a  day,  and  teeth  and  plate  cleaned. 

In  spreading  the  dental  arch  the  majority  of  cases  require 
the  greatest  pressure  on  the  anterior  teeth,  and  an  applhuuv 
that  can  be  placed  inside  the  arch  will  exert  the  greatest 
influence.  The  force  is  equally  distributed  on  both  sides  of 
the  mouth,  and  if  constant  the  work  will  be  accomplished 
rapidly,  without  inconvenience  to  the  patient.  Such  an 
appliance  is  here  illustrated  (Fig.  93).  It  is  used  in  the 
mouth  of  a  young  woman  fourteen  years  of  age.  A  plate  is 
made  to  fit  the  teeth  and  alveolar  process,  and  cut  awn 
that  the  anterior  parts  extend  far  enough  forward  to  inclose 


FIG.  93. 


the  teeth  to  be  moved.    A  piece  of  wire  is  bent  into  either 
of  the  forms  shown  in  Fig.  94,  wherein  a  is  the  coil 
point,  and  b  b  movable  arms  extending  from  a,  and 
points ;  c  c,  movable  arms  extending  from  b  b. 

Grooves  are  cut  into  the  anterior  and  poatene 
the  plate  to  correspond  with  and  receive  the  points 
c  c.     Holes  are  drilled  at  these  points,  and  the  wii 
the  rubber  plates.     In  order  that  the  anterior  teet 
moved  with  the  greatest  force,  the  arms  are  so  adj 
the  greatest  pressure  is  exerted  on  the  anterior  parts 
plates.     This  appliance  is  readily  removed  for 
and  returned  to  place  by  the  patient. 


130  IRREGULARITIES  OF  THE  TEETH. 

Another  appliance  for  >pivading  the  dental  arch  that  has 

!„„'.,.  jily  used  by  the  author  is  illustrated   in    Fig. 

-  ,,f  a  rubber  plate  made  to  fit  the  teeth  and  jaw. 

Tin-  pljit.-  i>  then  sawed  lengthwise— commencing  at  a  point 

anterior  !••  the  teeth  to  be  moved;  a  hole  is  drilled  at  the 

jMiint  \\heiv  the  slot  stops,  to  prevent  the  arms  breaking. 

At  the  extreme  end  holes  are  drilled  to  receive  the  spring. 

dju-t  the  plate  press  the  arms  together  and  drop  the 

plate  into  plan-.     Kiir.  iH5  shows  the  plate  out  of  the  mouth. 

This  can  !«•  removed  and  inserted  ad  libitum  by  the  patient. 

A  form  of  dental  irregularity  very  difficult  to  correct  is 

Km.  9.1.  FlO.  96. 


- ..: 


:ound  when  the  cuspids  are  situated  near  or  in  contact  with 

the  eentrak  while  the  laterals  stand  inside  of  the  arch,  and 

when  the  jaws  are  closed  pass  behind  the  inferior  incisors. 

laterals  are  in  near  relations  to  each  other,  it  is  by 

Unary  mean*  well  nin-i,  impossible  to  interact  upon  them 

'•'••i'-nt  pressure  to  force  them  apart;  the  space  being 

B  too  short  to  admit  a  jack-screw. 

Fig  517  repreeente  such  a  condition.    The  cut  is  made 
a*  of  a  case  in  practice,  the  patient  being  a  young 


eenycftM^ag^whoeame  under  my  care  in 

-Hperi,,r  laterals  were  then  only  one-fourth  of  an 


PART  II—  TREATMENT. 


firml      xe    Wll  oxyphosphate  of  zinc.    A  , 
bent  into  the  form  shown  by  Fig.  98,  the  ends  of     ,,.,. 
being  turned  at  a  sharp  angle  and  cut  short  as  sec,,  in  ,1,, 
figure. 

The  spring  was  then  put  in  place,  the  arm  ends  entering 
the  holes  in  the  collars,  and  the  curved  arms  found  to  be  so 

osely  conformed  to  the  surface  of  the  gums  and  palatine 

3  that  the  fixture  was  no  obstruction  to  occlusi.m.  and 

yet  could  be  easily  sprung  out  of  position  for  cleansing  pur- 


FIG.  98. 


poses  or  for  increasing  the  expansive  power  of  the  spring, 
by  simply  widening  the  lateral  spread  of  the  arms.  Fig.  97 
shows  the  progress  made  in  four  weeks'  treatment.  \Vhen 
the  laterals  had  been  moved  past  the  sides  of  the  centrals, 
they  were  by  other  means  forced  outward  into  line. 

KEGULATIXG  INDIVIDUAL  TEETH. 

To  force  out  central  and  lateral  incisors,  1  have  fmind  the 
following  methods  useful:  Around  the  tooth  to  be  in«.\vd. 
and  around  the  molars  as  nearly  opposite  the  direct i..n 
the  incisor  is  to  travel  as  possible,  fit  platinum  collars 
Solder  cups  upon  the  collars  directly  opposite  and  in  line. 
Make  a  spring  of  piano-wire  (Fig.  99),  and  spring  i 


, 


t 


OF  THE  TEETH. 

Fio.  100. 


Fio.  101. 


Fio.  102. 


PART  II — TREATMENT.  133 

the  cups  soldered  upon  the  collars.    In  Fig.  100  the  apj.!!:, 
is  seen  in  place. 

Another  method  is  to  make  a  plate  to  fit  the  teeth,  thick- 
ening it  nearly  to  the  cutting  edge  of  the  tooth  to  be  mov  ,1. 
arid  drilling  a  hole  through  the  thickened  part.  Dinvtly 
opposite,  at  some  convenient  point  on  the  back  part  of  the 
plate,  drill  another  hole  just  deep  enough  to  hold  the  spring 
in  place  (Fig.  101).  If  the  hole  in  the  thickened  part  be 
drilled  in  the  proper  place,  the  end  of  the  spring  will  hit  the 
tooth  midway  between  its  cutting  edge  and  the  margin  of 
the  gum.  This  spring  is  very  effective.  The  pressure  is 
constant,  and  the  spring  is  readily  removed  for  adjustment  or. 
for  any  other  purpose. 

We  frequently  find  a  single  tooth  situated  inside  the 
dental  arch,  and  have  trouble  in  contriving  an  apparatus 
suited  to  the  correction  of  such  an  irregularity. 

The  illustrations  represent  some  simple  appliances  that 
have  been  thoroughly  tested  and  found  satisfactory,  in  that 
they  do  the  work  effectively,  are  easy  of  adjustment  and 
removal,  and  may  be  readily  cleansed. 

Fig.  102  illustrates  a  second  inferior  bicuspid  of  the  right 
side,  having  a  lingual  presentation  equal  to  one-half  the 
thickness  of  the  tooth  inside  of  its  normal  position. 
cut   also  shows  teeth  in    other   malpositions,  but  for  < 
present  purpose  these  are  not  considered. 

For  this  case  a  thin,  narrow,  close-fitting  vulcanite  pla 
was  made,  and  a  hole  was  drilled  through  the  mid 
the  plate  opposite  the  centre  of  the  tooth  to  be  movec 
the  other  side  another  hole  was  drilled,  but  not  quite  thn, 
the  plate.     A  suitable  spring  (Fig.  103)  was  th,n  ma* 
piano-wire,  having  a  single  coil,  A,  and  the  ends  of  1 
bent  at  about  a  right  angle.     One  of  these  ends 
short  to  enter  the  corresponding  hole  m  the  1 ,  at, 
other  end,  B,  left  long  enough  to  go  through  the 
impinge  on  the  lingual  surface  of  the  birusj, 
fulfeighth  of  an  inch  between **  arm  of  * 
the  plate,  as  is  clearly  shown  by  Fig.  1 


134 


IRRKGUI.ARITIER  OF  THE  TELTH. 


|-,th  nmi".  n  B,  of  the  same  length,  to  pass  tlirough  the 
plat.-  and  impinge  «m  the  lingual  surfaces  of  teeth  upon 
QppOl 

in.')  slmws  an  appliance  for  pulling  out  the  central 


A 


FIG.  101. 
A 


An  illustration  of  the  manner  of  the  articulation 
will  he  found  in  Fig.  17,  page  35.     A  plate  is  innde  to  fit 
tin-  jaw  ami  teeth,  ami  into  it  were  vulcanized  two  of  the 
TalUt  springs  at  the  lateral  incisor  region.     The  wire  arms 
turnnl  into  loops  at  the  extremities  to  secure  a  ligature. 


Fi... 


th,.  pl.-.te  was  adjusted  the  arms  were  bent  liori/cn- 
broughl  inclose  proximity  to  the  lal.ial  surfaces 
ntral   in.-isors  and  securely  tied.     Hv   this  means 
ant  pressure  was  appli,,!,  and  the  teeth  were  carried 
outside  of  the  inferior  incisors. 


CHAPTER  V. 

TREATMENT  OF  SPECIAL  FORMS  OF  IRREGULARITIES. 
ROTATING  TEETH  IN  THEIR  SOCKETS. 
THE  FARRAR  METHOD. 

Dr.  Farrar  has  devised  for  this  purpose  a  modification  of 
his  "positive  system,"  which  is  illustrated  in  the  following 
cuts : — 


Fro.  10R. 


FIG.  108. 


FIG.  107. 
A 


Figs.  106  and  107  represent  screw-wrenches  ma dr  "f  1 
carat  gold,  with  the  exception  of  the  screw  in    I'V-  I"7- 
which  may  be  made  of  brass  or  steel,  as  dcsiivd.     If  tin- 
form  represented  in  Fig.  106  be  used,  it  is  adjusted  on  t 
tooth,  and  the  thin  gold  of  which  the  band  is  compa 
made  to  hug  it  by  tightening  the  nut,  B,  and  the  • 
bar,  F,  resting  firmly  against  the  adjacent  tooth  : 
the  nut  once  or  twice  a  day  causes  the  tooth  to  n 
the  box-wrench  (Fig.  107)  be  used,  the  arm  acts  u  ,- 
to  which  is  attached  a  band  of  rubber,  and  ligatun-  a* 
to  a  firm  tooth,  as  shown  in  Fig.  108.    Or,  both  forms  , 

135 


J36  IRREGULARITIES  OF  THE  TEETH. 

be  uacd.ns  in  Fig.  I"1-'.  ll>«'  P"^r  being  obtained  by  a  scivw 
nitiiiiiiu'  in  a  ^vivrl.  A',  attached  to  a  distant  tooth.          , 

in  ..mil  111   show  another  form  of  apparatus,  so 
siinjili-  and  so  plainly  shown  by  the  cuts  as  to  require  little 
•iption.     The  strip  of  plate  resting  on  the  palatal  sur- 
feoea,  of  the  adjoining  teeth  serves  as  a  fulcrum,  and  the 
tooth  operated  on  is  rapidly  drawn  into  line  and  rotated. 
1  in  represents  an  actual  case  treated  by  Dr.  Farrar,  and, 
;,„  },.  the  patient,  about  thirty  years  of  age,  manipu- 

lated the  apparatus  himself,  reporting  only  once  during  the 
week  that  the  operation  was  in  progress. 

Fig.  11-  illustrates  a  right-angle  key  or  wrench,  with 
Level  pinions  similar  to  the  right-angle  engine  attachments 
which  Dr.  Farrar  uses  for  turning  nuts  in  localities  such  as 
that  shown  in  Fig.  110,  or  in  other  localities  where  it  is  dif- 
ficult to  use  the  ordinary  wrenches. 

l>r.  Farrar's  "  triplex  system  "  is  also  adapted  to  the  treat- 
ment of  cither  of  these  varieties  of  irregularity,  as  illustrated 
in  Fig.  113.    "The  bearings  of  the  bands  upon  the  different 
|M)ints  of  the  teeth  and  the  directions  of  their  movement  are 
indicated  by  the  arrows,  while  the  details  of  construction  are 
shown  in  the  figure,  and  the  device  is  made  as  follows  :  A 
stitf  strip  of  plate,  T,  is  bent  on  a,  form  to  loosely  fit  the  necks 
of  the  teeth  at  certain  points  under  the  free  margin  of  the 
jruins.  and  prevent  the  plate  from  slipping  from  the  teeth; 
and  the  <-nds  of  the  plate  are  so  shaped  as  to  bear  firmly  on 
the  distal  comers  of  both  teeth.     These  bearings  may  be 
••lian-rd  l,y  properly  bending  the  ends  of  the  plate  as  the 
"l-en.tion  advances.    The  bridge,  C,  carries  two  rollers,   H' 
n  which  the  thin  ribbon  loop,  /,,  passes,  and  is 
1  it<  fold  on  a  wire  attachment  to  the  middle  of  bar, 
shown  in  position  on  the  tooth.   The  screw,  S,  is  swiveli-d 
*  tf  end  of  the  metallic  ribbon  loop,  and  screws  into  the 
'•"'I-  with  the  effect  of  separating  the  ends  of  the 
"'!'   thus  moves  the  bridge  toward  the   bar   and 
Mates  both  incisors. 

modifications  of  this  device  may  be  adapted  to 


PART  II— TREATMENT. 


137 


*WI 

different  presentations  of  this  class  of  cases,  the  main  thing 
to  be  kept  in  view  being  the  points  of  bearing  of  the  bri.l^ 
C,  and  the  bar,  T;  for  while  the  apparatus  will  work  ^ 


FIG.  109. 


FIG.  110. 


FIG.  111. 


FIG.  112. 


FIG.  113. 


10 


JRRWJULARITIES  OF  THE  TEETH. 

when  the  teeth  have  small  necks,  it  is  difficult  of  retention 


ui->n  taiN-rng  teeth.  .      .      -, 

-  in  nmeou^  a  firmer  hold  on  the  teeth  may  be  obtained 
l,v  u  ..air  ..f  narrow  loops,  the  folds  of  which  pass  on  either 
,,,-  )h(.  l,;ir.  around  the  ends  of  a  pin  pass..,-  through 
imd  nmj.rtii.Li  from  the  middle  of  the  bar,  as  shown  in  I-  ig. 
HI  Tin-  har  thus  made  and  connected  is  easily  detached 
bribe  pupae  of  bmding  its  arms  to  obtain  rotative  bear- 
in-:*.  A  key  f..r  turning  the  screw  may  be  readily  made 
fn.in  an  .•\ravat<.r.  shaped  as  shown  at  K,  Fig.  114." 

THE  (iriLKOBD  METHOD. 

Dr.  S.  lUiuilford  has  devised  a  little  fixture  for  correct- 
ing malposition-  of  the  central  incisors,  shown  in  Figs.  115 
and  !!»'•.  At-c'inling  to  his  description,  it  is  constructed  as 


Km.  115.  Fio.  116. 


follows:  A  piece  of  gold  backing  one-eighth  of  an  inch  wide 

and  sufficiently  long  to  extend  along  and  a  trifle  ln-yund  the 

palatal  >urfai-es  of  the  centrals,  is  bent  to  conform  as  closely 

as  possible  to  their  lingual  surfaces,  and  forward  so  a>  \<> 

-lightly  clasp  (lie  disto-palatal  angles,  as  shown  at  Fig.  1 17. 

To  this  are  Mildi-n-d  two  strips  cut  from  plate-scrap,  u  little 

narrower  than  the  first  pieee.jmd  bent  in  the  form  of  //  and  c 

117 1.  n-peetively.  which  are  sufficiently  long  to  extend 

•ly  over  the  anterior  and  posterior  surfaces  of  the  teeth. 

hem-:  pruperly  shaped  to  fit  the  model, their  backs  are 

-old.r.d  t.MMherand  to  the  part, as  shown  in  Fig.  118.    The 

part    h  r,  which    passes    between    the   teeth,  is 

^1T       reduced  sufficiently  with  a  file,  or  the   teeth 

^^^**s  may  be  separate.  1   l,y   wedging,   to   allow  the 

insertion  of  the  fixture.     The  labial  part  should  rest  against 


PART  II— TREATMENT.  139 

the  teeth  just  at  or  slightly  above  the  most  prominent  part 
of  the  convexity,  while  the  lingual  portion  should  be  near 
the  gum,  but  not  quite  touching  it.  The  slightly-mm-d 
ends  will  catch  just  above  the  little  nodule  usually  found  on 
the  disto-palatal  angle  near  the  gum.  Thus  secured,  it  can- 
not be  easily  displaced.  Bend  the  long  palatal  arms  slightly 
toward  the  short  labial  ones  daily,  and  spring  them  int.. 
position  on  the  teeth.  The  elasticity  of  the  gold,  stiffen «•<! 
by  the  solder,  will  do  the  work.  "  By  this  means,"  says  Dr. 
Guilford,"  the  use  of  all  rubber  or  silk  ligatures,  so  irritating 
to  the  gum  and  so  painful  in  application,  is  dispensed  with." 
Fig.  115  illustrates  a  case  treated  by  Dr.  Guilford  with  this 
appliance,  the  cure  being  complete  after  a  treatment  of 
ten  days,  the  patient  having  been  seen  every  day.  The 


FIG.  119.  FIG.  120. 


general  form  of  the  appliance  is  also  equally  useful  in  cor- 
recting teeth  in  the  reverse  position,  shown  in  Fig.  116. 
this  case  the  construction  is  reversed,  so  that  the  long  arm  • 
band  may  rest  on  the  labial  and  the  short  one  on  tin-  pal 
surfaces,  and  so  bent  as  to  throw  the  distal  angles  mwa 

The  same  appliance  slightly  modified,  he  says, 
ful  for  rotating  a  single  incisor  where  its  mate  , 
position.     In  this  case  the  end  of  the  appHance  is  _l,i 
nicely  to  the  tooth  in  position,  while  the  other  halt 
shaped  as  to  give  the  desired  pressure  on  the 
rotated.  THE  AUTHOR,S  METHOD. 

In  June,  1884,  the  following  treatment  Wi 
for  rotating  the  central  incisor  of  a  patient 
band  was  made  to  fit  the  tooth,  and  a  tube  of  the 


IRREGULARITIES  OP  THE  TEETH. 


140 

.ia,  W1W  soldered  lengthwise  with  the  band  (Ffc.  L19). 
.ecoied  to  the  tooth  with  the  oxyphoephate 

:.::':;:::  .....  fi^^^^wA 

all(iwt.(1  „  ,.,,,„,!  to  the  left  central  incisor  (Fig.  120). 

<  l,,nt  every  day,  and  the  tooth  thus  rotated  into 
,1    '  Wh,n  practicable,  we  should  solder  a  flat  tube  to  the 
Ld'  for  the  purpose  of  holding  a  flat  lever,  which  would 
prvvi-ut  tin-  rotation  of  the  arms. 

MOVING  CROWNS  AND  ROOTS. 

In  most  of  the  operations  for  regulating  teeth,  the  apices 
of  the  roots  are  in  a  position  either  normal  or  approximat- 


Ki..   121. 


\\\X  to  it  iii  siu-h  a  decree  as  not  to  require  moving.  I>ut  in 
uome  cases  it  hi-nums  necessary  to  move  the  whole  root 
For  this  puqiose,  although  the  power  may  be  the  same,  yet 
it  must  IK-  iiuuli'  to  act  in  a  different  manner. 

In  ordinary  moving  of  teeth,  the  power  is  at  one  end,  the 
•  UKv  at  the  other,  while  the  fulcrum  is  in  the  middle  <>i 
tin-  tooth  to  be  removed.    This  is  illustrated  in  Fig.  121, 
vli.-iv  r  \<  thr  power,  .F the  fulcrum,  and  S  the  resistance. 
|M.\ver  being  continued,  the  teeth   arc  drawn   in  the 
tion  indicated  by  the  arrows,  [7.     The  first  effect  of  this 
movement,  so  far  as  the  roots  are  concerned,  will  be  to  cause 
t<»  impinge  against  the  septum  B,  at  the  point  F,  and 


PART   II— TREATMENT.  J41 

also  against  the  socket  wall  at  the  point  8.  They  will  also 
separate  from  the  sockets  at  the  points  A  and  C',  as  indicated 
by  the  arrows.  If  the  force  be  continued  in  this  diiv,-ti,,n 
until  the  points  touch,  as  in  Fig.  122,  the  lever  is  chan-:.-.! 
into  one  of  another  variety,  in  which  the  power  is  applied 


FIG.  123. 


between  the  fulcrum  and  the  resistance  (X,  Fig.  122).  Thus, 
the  same  power  from  the  same  apparatus  acts  in  exactly  the 
opposite  manner,  causing  the  roots  to  approach  each  otlu-r 
throughout  their  length  (the  fulcrum  being  at  0,  Fig.  ! 


FIG.  125. 


Fir,.  126. 


and  leave  the  socket  walls  in  the  same  manner.    Fig.  1 
shows  the  completion  of  the  operation. 

The  appliance  used  by  Dr.  Farrar  in  this  open* 
shown  in  Figs.  125  and  126.    "  It  is  mad,  up  of  I 
clamp  band  to  draw  the  teeth  together,  and  ft  lock  poi 


j  ,-j  lUUKGULARITIES   OF  THE  TEETH. 

to  hold  rfrfdnaiy  the  cutting  edges  of  the  teeth;  Imt  while 
,,„.„,,!,  aw  being  drawn  together,  only  the  band  portion 

,„,,!  |H.  wed  on  each  extremity  <>f  a  band  made  ..t  lighl 
Hlll|  .tron-  n.lled  win-  is  soldcn-d  a  nut,  one  of  them  being 

i  \v  nut  Tli rough  these  nuts  pa^e<  a  little  gold  screw, 
havimr  a  head  titled  to  a  watch  key.  Tin-  main  point  to 
li.'.l.l  in  view  in  constructing  this  elanip  portion  is  to  insure  a 
(.|o,c  iN-aring  at  the  -ruin  border,  to  prevent  it  from  slipping 
,,tr  tin-  teeth.  The  lock  portion,  for  preventing  the  over- 
lapping of  the  crowns  when  the  force  is  continued  after  the 
teeth  have  hc,-n  brought  in  contact,  is  a  simple  device,  easiest 
mad.-  by  U-nding  a  -mall  piece  of  plate  about  one-<|iiarter  of 
an  inch  xjuaiv.  «.r  a  little  larger,  trough-like,  so  as  to  fit  the 

-  of  the  teeth  :  to  this  is  soldered  at  right  angles  another 
,,f  plate  extending  far  up  between  the  teeth  nearly  to 
the  ..MUM  :  on  the  upper  end  of  this  is  soldered,  tran-\  eisely, 
alH.ut  one-eighth  of  an  inch  of  small  tubing  (smooth  bore). 
through  which  passes  the  bolt  of  the  clamp  band  and  from 
which  it  is  loosely  suspended.  This  part  (the  trough  por- 
tion) may  be  constructed  skeleton-like,  as  shown  by  Fig. 
1  •_'•".  and  is  more  easily  kept  clean.  The  clamp  is  first 
applied,  the  force  being  interniittingly  applied  two  or  more 
times  a  day.  or  every  time  the  band  loosens  by  the  move- 
ment of  the  teeth  :  but  this  should  never  be  powerful  enough 
to  eau-e  pain.  After  the  teeth  are  brought  in  contact  or 
nearly  «..  the  inm-h  portion  is  added,  and  the  force  of  the 
clamp  hand  continued  until  the  roots  are  brought  into  the 

••d  position." 

FORCED  ERUPTION  OF  THE  TEETH. 
THE  MATTESON  METHOD. 

Mally  a  single  impacted  tooth  in  the  jaw  does  not 
work  its  \\-ay.luwn  sufficiently  to  occlude  with  its  opposite 
t-H.th.  or  the  incisors  do  not  meet  when  the  jaws  are  closed. 
Such  teeth  are  to  be  treated  so  as  to  make  them  as  nature 
ntended.  Dr.  A.  K.  Matteson,  of  Chicago,  has  been  success- 
ful in  using  the  following  methods :  A  rubber  plate  was 


PART   II — TREATMENT.  143 

made  to  cover  the  roof  of  the  mouth  and  to  fit  the  necks  •  if  the 
teeth  closely,  a  French  clock  spring  being  adjustc.l  with  one 
end  riveted  into  the  central  posterior  part  of  the  plate   i 
127) ;  when  the  spring  was  inserted  and  forced  up  again-' 
plate,  the  distal  end  of  the  spring  touched  the  necks  of  tin- 
teeth  to  be  drawn  out;  ligatures  were  then  fastened  to  tin- 
necks  of  the  teeth,  and  the  spring  carried  up  to  tin-  pi  ate  ami 
fastened  to  the  teeth.     If  the  spring  be  sufficiently  powerful, 
from  two  to  four  teeth  may  be  operated  upon  at  one  time. 

The  spring  being  movable  upon  the  rivet  in  the  plate,  one 
tooth  at  a  time  can  be  erupted,  and  then  the  point  of  tin- 
spring  may  be  turned  to  the  next  tooth. 


Fig  128  shows  a  similar  appliance  for  erupting  th-  fyili 
on  the  lower  jaw.    Erupting  teeth  is  u,,lik,  jnyof  ( 
regulating  operations,  as  no  pressure  to  produce 

"  Zen  tteral  pressure  has  been  removed.,!,.  ,nild,,,  ^ 
is  sufficient  to  draw  a  tooth  out  of  the  pM£  - 
are  conical  and  the  pressure  is  diredcd  away  to 
instead  of  against  it, 


THE  AUTHOR'S  METHOD. 


J44  IBRKcM  I .AKITIES  OF  THE  TEETH. 

n.,,tiv  -f  the  space  made  l.y  the  missing  tooth  (Fig.  1'J'.'). 
Tin-  hoi.-,  wliirli  i<  smaller  than  the  coil-wire  spring,  holds 
one  arm  of  the  spring.  The  other 
arm  (ii})on  the  end  of  which  a  loop 
has  been  made)  meets  the  neck  of 
the  tooth  to  be  moved,  and  is  there 
-•mred  with  a  ligature.  It' the  tooth 
l»c  imbedded  in  the  alveolar  process 
and  a  ligature  cannot  be  bound  to  it, 
a  platinum  hand,  with  a  hook  sol- 
dered upon  it,  may  be  forced  up 
under  the  gum  and  secured  with 

ovvptio>phatc  of  zinc.  Should  this  fail,  as  a  last  iv-ort  a 
huh-  may  U-  drilled  into  the  crown,  and  an  eyeholt  fastened 
in  with  ceiii.-nt,  to  which  a  spring  may  be  fastened  with  a 
ligature.  If  inure  spring  to  the  wire  be  required,  the  hole 
may  IK- drilled  in  the  plate  at  a  longer  distance  from  the 
(•".til  t<>  !>«•  moved,  thus  giving  a  greater  sweep  to  the  arm. 


CHAPTER  VI. 

PROTRUDING  TEETH. 

KINGSLEY'S  CASE. 

The  following  case,  with  the  accompanying  illustrations 
is  reported  by  Dr.  Kingsley  :— 

Fig.  130  shows  the  condition  of  the  teeth  of  a  child  of 
nine  years  of  age,  for  which  no  -adequate  cause  could  be 
given,  as  it  was  not  hereditary  nor  the  result  of  thunilt- 
sucking.  Treatment  was  not  begun  until  the  patent  \v;i< 

Fin.  130. 


when  the 


had  all 


•- 


:    -  ..... 


,46 


,KUF,-I  I.AUITH-   OF  THE  TEETH. 

forward  and  .-au^ht  ,,n   projecting  spurs  of  the  gold 


-Ina  <hort  time  tlu-  arch  in  front  was  contracted  until  the 
w«n  in  contact,  but  it  was  not  sufficiently  reduced 
loom  being  essential,  the  first  bicuspid  on  each  side 
removed  The  incisors  had  appeared  to  lengthen 
during  tl..-  prongs  (although,  probably,  they  had  not  actu- 
ally done  -o).  and  it  seemed  that  they  would  eventually  come 
,!„„„  »«*  to  touch  the  gum  of  the  lower  jaw.  The  attempt 
•Ii.-n-f"iv  ina.lr  to  shorten  the  crowns  by  driving  th.-m 
up  into  tin-  jaw.  Tin-  fornu-r  appliance  was  continued,  and 


to  tin-  poM  franu'  was  added  a  stud  or  post  about  one-half  an 

iiu-h  long, soldered  to  it  opposite  the  cuspids,  and  coming 

li  ronu-r  of  the  month."     This  apparatus  is  shown 

in  Kip.  131.    The  arms,  extending  upward,  passing  outside 

"•'  k-.  wen-  made  of  strips  of  brass  and  connected  by 

elasti.  ligatures,  with  a  leather  skull  cap,  as  shown  in  Fiu.  1  :!± 

Tin-  vulcanite  plate  was  in-erted  in  the  mouth,  and  the 

robber  llgttarw  bn.upht  forward  and  caught  ;  the  skull  cap 

was  then  placed  on  the  head,  and  strong  elastic  straps  were 

caught  over  buttons  or  hooks  on  the  cap,  and  like  buttons  or 

hooks  on  the  cheek-arms,  as  shown  in  Fig.  132.     The  outside 


PART   II — TREATMENT. 


147 


pressure  thus  forced  the  teeth  up  into  the  jaw,  and  tin-  ii 
pressure  drew  them  backward  in  a  direct  line.  TV  a].],a- 
ratus  did  not  interfere  with  the  comfort  of  the  patient,  ami 
was  worn  for  three  months  constantly,  and  part  of  the  time 
for  two  months  more,  at  which  time  the  six  front  trctli  \\viv 


Fin.  13>. 


FIR.  133. 


the  result  shown  in  Fig.  133. 


148 


IRREGULARITIES   OF  THE   TEETH. 


FARRAR'S  CASES. 

When  tin-  abnormal  protrusion  of  the  six  upper  front 
tit-tli  i-  v.-ry  marked,  the  correction  of  the  irregularity  may 
rvi|iiire  a  ^renter  degree  of  anchorage  than  is  afforded  by 
tin-  interior  terth.  Dr.  Farrar  has  devised  an  appjmitu.-  to 
,  cases,  known  as  a  "bridle  apparatus,"  which  is 
illustrated  in  Fig.  134. 

Tlii^  i-  constructed  as  follows:  "A  gold  strap  of  rolled  \viiv, 
havini:  a  smooth  nut  on  each  end,  is  bent  to  conform  to  the 
anterior  surface  of  the  four  or  six  front  teeth,  and  so  fastened 


1 


!'-v  n"':l11^  "''  -  ''lamp  Viands  on  the  posterior  teeth,  as 

shown  in  Kijr.  1:;."). 

T- prevent  tliUhaml  from  slipping  up  toward  the  uuni 

"u^hs  have  I,,-,.,,  tried,  hut  they  collect  food  and  injure  the 

"He  .„•  more  T  pieces  made  to  fit  between  the 

ll<ll'IV'1  "'  tin-  hand,  or  to  ferrule,  sliding  on  the 

85  and  UM.ortobroad  plate  hooks  (Fig.  139). 

r  l'1:m  "f  "ttainin^  this  end   is  hy  the  use  of  a 

Qg  upou  the  liu-ual  surfaces  of  the  teeth, 

111  *e  same  way  to  the  front  Land  (Fiu-    ]:;,;, 


PART   II — TREATMENT. 


149 


The  nearer  these  front  wires  approach  the  cutting  edg« 
the  teeth,  the  less  power  it  requires  to  move  the  teeth. 

"  The  front  band  is  connected  with  the  outside  apparatus 
by  means  of  cylindrical  or  angular  ferrules,  or  staples  sol- 
dered to  it  at  points  opposite  the  spaces  between  the  lateral- 
and  cuspids.  Through  these  ferrules  or  staples,  which  are 
at  a  sufficient  distance  from  the  corners  of  the  mouth  to 
prevent  the  dribbling  of  saliva,  are  hooked  bent  cheek -\viiv>. 


FIG.  135. 


gold  (about  No.  12  gauge),  that  project  t,,nvan  »  •  _ 
ward,  thence  pointing  toward  the  e»s  <;»  '.',',',.  * 
front  band  (Fig.  134).  To  preven  «£  •  fcj 
curved  cheek-wire,  one  side  of  the)  m 

flat,  and  the  ferrule  shaped  to  correspond 
a  hammer;  but  this  is  seldom  »•».      ,     ,„,,      „. ,. 

"In  some  cases,  in  '«****•"    'b     „,,,,,-,,!  to«* 
of  no-consideration,  the  cheek-wires  «u>  b 


100  IRKKJI'LARITIEB  OF  THE  TEETH. 

to  tli.-  front  l>an<l  piece  (the  retaining  portion  of  the  in-ill.- 

H|'|uimtiis  IK-UI^  <li-pensc.l  with,  Fig.  136),  or  double  band, 

.iiwn  in  Fig.  l-'!7.     The«>uter  extremities  of  these  check- 


win- an-  .screw-cut  for  drag  nuts,  one  modification  of  which 
bfltateated  l.y  K,  137. 

H  \\iivs  may  be  in  two  or  more  pieces,  but  as  this 


»W<«  "»<*«*,  which  may  crowd  upon  the 

W^  |»^.  of  the  mouth,  it  >  much  better  to 

-m  one  piece,  which,  if  l „„„  properly, 


PART   II— TREATMENT.  J-j 

will  arch  from  the  cheek  to  the  ear-ring  without  hein^  jn 
contact  Avith  the  cheek. 

"In  fact,  my  experience  teaches  me  that  the  latter  is  much 
the  better  form.  The  screw  extends  through  the  holes  in 
opposite  sides  of  a  small  ring,  which  is  caught  on  our  (,f 
several  hooks  soldered  to  a  much  larger  ring  extending 
around  the  ear  of  the  patient  (Fig.  134).  This  lar^r  ring 
(which  is  necessary  to  prevent  interference  with  tin-  ear) 
is  fastened  to  inelastic  straps  extending  around  the  hack 
of  the  head  and  held  in  place  by  other  straps,  as  -hown. 
The  loAver  straps  and  ear-rings  constitute  the  uneh" 
apparatus.  The  ear-rings  should  be  about  IAVO  and  a  half 
by  three  inches  in  diameter,  underlaid  by  soft  leather  or  felt 
rings  about  one-quarter  to  one-half  inch  wide,  to  >«  r\ 
cushions  to  protect  the  skin.  In  order  to  have  the-e  ring- 


FIG.  138.  FIG.  139. 


rest  in  their  proper  places  around  the  ears,  and  \<>  i«-nmt 
the  harness  to  bear  equally,  so  as  to  prevent  headache,  tl 
several  straps  should  be  made  capable  of  being  tigfa 
loosened  at  will  by  means  of  buckles. 

-When  the  apparatus  is  in  position,  the  firienda 
patients  are  instructed  to  tighten  the  posterior  Uiu 
turn  the  nuts  within  the  smaller  rings  da  ily. 
is  advised  to  call  at  the  office  once  or  tui.v  a  u 
the  position  of  the  teeth  has  changed  suffic.enlv  to  1 
the  front  bands  liable  to  slip  off,  the  dm,t,,n  • 
should  be  changed  by  raising  the  nut  ring  from  a  1- 

'  " 

on  the  ear-ring  to  one 
" 


to  the  profession  by  Dr.  Fnrmr 


152  iKUKca-I.AKITIES  OF  THE   TEETH. 

sj,ts  of  bands  of  gold  or  platinum  extending  around 
flu  molar-  an-1  bicuspids  upon  cither  side  of  the  arch.  A  nut 
l.U-red  UIN.II  tlu-  Imccal  surfaces  for  carrying  a  long  screw. 
A  band  of  gold  encircles  the  arch,  and  is  secured  by  hooks 
Jm.lwuv  between  the  rutting  i-dgrs  and  mrks  of  the  Lncisoi 
t.i-tli.  The  ends  of  the  hand  are  bent  at  right  angles,  hav- 
ing hole-  through  the  ends  for  the  free  movement  of  the 
acre**.  The  hands  and  teeth  enclosed  are  the  fixed  point-. 
and  by  turning  the  screws  twice  a  day  the  anterior  teeth  are 
nirri.il  t->  the  posterior  part  of  the  alveolus.  This  appliance 
rlaim-  cleanliness  and  the  advantage  of  being  out  of  sight 
ta  >trong  (Niints  for  its  recommendation  to  our  use. 


Km.  140. 


-: 


PROTIM  SION  OF  THE  INFERIOR  MAXILLA. 
ALLAN'S  CASE. 

FIJI.  141  reprints  a  case  of  protrusion  of  the   inferior 

:!ary  treat. -d  l,y  Dr.  George  S.  Allan,  of  New  York. 
The  irn-giilarity  {.ertaining  solely  to  the  jaw,  that  alone 

"-11  "I A  brass  plate  was  made  to  fit  the  chin, 

not  with  honked  ends  arranged  so  that  the  distance 

''"•'"  «-"uld  he  altered  by  pressing  then,  apart  or 

A  network  was  adjusted  upon  the  head,  having 

""  <»chgide,OIie  above  and  the  other  below  the 

"•!>  *ew attached  foupligatofee  ,,f  onlinarv  elastic 

opewtion  proceeded  rapidly,  and  at  the  end  of 


PART  II—  TREATMENT. 


loo 


cartilage 


METHODS  OF  EETENTION 

No  element  of  regulating  the  teeth  is  more  difficult  ,ln, 
that  of  securing  the  teeth  firmly  after  they  have  Jn  fo 


Fro.  141. 


into  their  new  positions.  The  inclination  to  ivtimi  t<>  tln-ir 
original  places  is  increased  when  the  teeth  ;irc  nmvfl  t'a-ti-i- 
than  the  physiological  process  of  filling  in  new  material  i- 
accomplished.  Pressure  of  the  lips  and  tongue  exerts  influ- 
ence in  producing  backward  and  lateral  pressure  UJKHI  tin- 
teeth.  The  greatest  help  in  this  direction  is  t<>  ->  plan 
the  operation,  either  by  extraction  or  by  inward  or  outward 
pressure  (as  the  case  requires),  that  when  completed  thr 
posterior  teeth  will  occlude  in  such  a  manner  that  they  will 
11 


|54  IKKKUITLARITIES  OF  THE  TEETH. 

hold  one  another  iii  proper  positions.     Dr.  Kinsley,  in  his 

1  Defctmtties/'says:  "The  articulation  of  masticating 

,,f  iinu-h  more  importance  than  their  number,  and 

a  |mij,,,|  number  of  grinding  teeth  fitting  closely  on  occlu- 

-i..n  will  l>e  of  tar  -rivater  benefit  to  the  individual  than  a 

mouthful  «.f  teeth  with  the  articulation  disturbed."* 

Occlusion,  however,  will  not  retain  the  anterior  teeth  in 
lotion.  Nor  will  it  be  safe  to  depend  entirely  upon  occlu- 
MIIII  to  hold  th<-  interior  teeth  in  position.  In  most  cases 
other  menn<  must  be  devised  for  holding  the  anterior  teeth 
in  iMisition.  Cases  of  this  kind  are  apt  to  be  those  in  which 
th«-  an-h  of  the  superior  or  inferior  maxilla  has  been  spread 
or  the  anterior  teeth  have  been  moved  inward  or  outward. 


It   i-  then  frequently  necessary  to  spread  both   arches   by 
-imply  carrying  the  teeth  of  one  jaw  out  to  the  proper  dis- 
tance and  M,-imi,,r  ,}„.„,  wjth  a  retention  plate;  the  teeth  of 
'!"•  "piH.sit,.  jaw  will  in  most  cases  be  forced  into  their  p«.<i- 
!•>•  their  grinding  surfaces  coming  in  contact  in  nms- 
"•ation.    Fig.  142  shows  one  of  these  retention  plates.    It 
J  roof  of  the  mouth  and  teeth  accurately,  and  can  be 
removed  for  cleansing.    Such  a  plate  is  of  service 
ither  jaw  for  preventing  one  or  all  the  teeth  from 
back  toward  the  inner  part  of  the  mouth. 


"/'•  "'/-,  p.  43. 


PART   II—  TREATMENT. 

loo 

KIXGSLEY'S  RETAINER 


cation  w,ll  not  serve  when  the  teeth  are  crowded 

RICHARDSON'S  RETAINERS. 

Where  all  the  teeth  in  the  jaw  have  been  moved,  particu- 
larly if  some  have  been  rotated  into  position,  a  retentive 
plate  that  comes  in  contact  with  all  the  teeth  should  be 


FIG.  143. 


used.  A  rubber  plate  will  fit  each  tooth  accurately  without 
trouble  or  expense.  Dr.  Richardson  gave  his  retentive  plate 
to  the  profession  many  years  ago,  and  in  many  respects  it 
cannot  be  improved  upon.  Fig.  144  illustrate*  this  appli- 
ance. It  is  composed  of  two  pieces  of  rubber,  vulcanized 
upon  the  labial  and  lingual  surfaces  of  the  teeth  of  the 
plaster  model.  These  are  trimmed  to  about  a  quarter  of  an 
inch  in  width,  and  fitted  to  the  necks  of  the  teeth  and  gums. 
When  a  tooth  is  missing  upon  either  side  of  the  jaw,  or  when 
spaces  exist  between  the  teeth,  or  there  is  room  In-hind  the 
molars,  the  rubber  may  extend  from  the  outer  to  the  inner 


,M  IRRBOO.ABITIE8  OF  THE  TEETH. 

„  I  ihu<  Hi''  two  l'ieees  •>*  mnde  int°  °"e'     K>  "'*  '" 
!  "",,,    .'I,     n  ,     ,v  te  little  or  no  room  to  carry  the  rabbet 

";;•;,  »,«»«*«  -ndgoM  wire  may 

"  vuln...  »<l  »r  nv,,,,l  *>  as  to  hold  the  w.n>  in  pos.tion. 
.,.,„.  ,,,,lv  ,,l,j,Hi,.n  „.  this  appliance  s  its  unsightly  ap- 
,«,n.i..v  It  MB,  however,  I-  iv"."v,,l  by  the  patient  for 


i;l  l-.IU.i;  ri.ATKS  WITH  GOLD  BANDS  AND  BARS. 

When  sinirle  teeth  have  been  rotated  in  their  sockets,  or 
in  or  out  for  the  purpose  of  perfecting  the  contour,  a 
,  arrangement  for  retaining  the  teeth  is  to  fit  a  rubber 
to  the  palatine  or  lingual  surfaces  of  the  teeth,  and 


Vl... 


Flo.  14--,. 


attach  a  liar  or  clasp  of  gold  to  the  teeth  that  have  IKVM 
iuovc<l.  Ki_i,r.  II")  illustrates  a  retaining  plate  with  a  l>ar 
attaclinl  for  holding  the  superior  central  incisors  in  their 
ixi-itioii  after  regulating.  The  bicuspids  and  molars  may  In- 
••••I  -ituilarly. 

KuhU-r  retainers  are  apt  to  be  inconvenient  for  cleansing 
properly.  Patients  are  inclined  to  be  careless  on  this  account. 
hut  sliniiM  In-  instructed  to  attend  to  this  duty  after  ea<  li 
BMal to  prevent  the  secretions  from  becoming  vitiated,  the 
JIUIIIH  intlaiued.  and  the  U-etli  decayed.  Great  improvements 

these  appliances  have  heen  made  in  the  past  few  years,  as 
will  W  observed  on  examining  some  of  the  methods  below. 


PART  II— TREATMENT.  157 

FARRAR'S  RETAINERS. 

Dr.  FarrarX  New  York,  has  invented  some  in,,,,i,,u>  Ap- 
pliances for  holding  teeth  in  proper  positions,  called  -  Retain 
mg  or  Anchor  Clamps."    Some  are  composed  of  one  piece  .,f 
gold,  others  of  two  pieces.    Those  having  one  piece  ( I 
are  made  from  square,  18-carat  gold  wire.    This  will  '"takr  a 
size  to  correspond  with  the  tooth  and  the  amount  of  reewt- 
ance  required  to  hold  it  in  place.    A  thread  is  rut  fn,,,,  one 
end  to  about  a  third  of  its  length,  the  remainder  of  th.-  win- 
is  rolled  or  hammered  into  a  thin  band,  about  No.  35  .. 
American  gauge,  and  about  one  twenty-fourth  of  an  inch  in 
breadth.     At  the  distal  end  a  hole  is  drilled,  large  enough 
to  allow  the  screw  end  to  pass  through  with  a  thread  cut 
upon  it.     Small  projections  should  be  soldered  upon  tin- 
band  and  bent  so  as  to  catch  upon  the  tooth.     Wlu-n  \\\-» 

FIG.  146.  FIG.  147.  Ki.;.  148. 


pieces  of  gold  are  used,  the  band  is  made  in  the  manner 
described  in  the  first  case,  and  bars  of  the  same  carat  <.r"l«l 
rolled  to  Nos.  22  and  23,  American  gauge.  One  end  of  Un- 
bar is  bent  to  an  angle  of  forty-five  degrees  to  prevent  tin- 
band  from  slipping.  Near  the  other  end  of  the  bar  a  hole 
is  drilled  for  the  passage  of  the  screw  end  of  Fig.  147. 

Both  bands  may  be  used  for  rotating  teeth  in  their  sockets 
and  also  for  retaining  them  in  place.  Fig.  148  show-  I  >v. 
Farrar's  retaining  band  in  position. 

DR.  MAGILL'S  BETA  IN  Ki;. 

Dr.  Magill's  retainer  consists  of  a  band  of  gold  or  plati- 
num (Fig.  149)  swaged  or  fitted  accurately  to  the  tooth 
of  sufficient  strength  to  resist  the  rotary  strain  and  fricti- 
mastication.     By  trimming  the  labial  surfaces  as  narm 


IKKEOULARITIES  OF  THE  TEETH. 

with  strength,  the   band  will   not   appear  con- 
,,„,.    It  ^hould  U' adjusted  midway  between  the  cutting 
•iu.ling  edges  and  the  gum,  and  there  cemented  to  the 
t.Hith  with  oxypli.xphate  of  zinc.     This  can  be  worn  indefi- 
nitely without  atfecting  the  gums  or  teeth,  and   can   he 
cleansed  perfectly:  hence  tin-  hands,  Lars  or  levers  may  be 


Fni.  H9. 


FlO.  150. 


finnly  >ol. It-red  for  rotating  or  retaining  the  teeth  after 
regulating.  Fig.  150  shows  the  application  of  one  of  these 
device-,  when  two  teeth  a iv  secured  in  position  by  a  bar  ex- 
tending past  fixed  trrth  on  both  sides.  When  two  or  m<>iv 
t.t-th  an-  to  !»»•  held  in  position,  the  Itands  may  be  secured 
to  the  bicuspids  or  molars  on  both  sides,  and  a  bar  of  gold 


FIG.  151. 


d.-d  from  one  to  the  other,  upon  the  lingual  or  labial 

surface,  as  illustrated  in  Fig.  151,  from  Dr.  Guilford's  colh'.- 

"  1'latimim  hands  \veiv  fitted  to  the  two  cuspids,  and 

•••••••nnect.-d  l,y  a  very  thin  platinum  wire  passing 

along  and  conform  in-  to  the  outline  of  the  labial  surface's  of 

the  1 


PART  II—  TREATMENT.  159 

THE  AUTHOR'S  RETAINER. 

This  retainer  consists  of  a  band  of  platinum  or  gold  titt«-«l 
.to  the  tooth  or  teeth,  with  a  tube  of  the  same  material.  th«- 
width  of  the  tooth,  soldered  lengthwise  of  the  band,  as  illus- 
trated in  Fig.  152.    The  band  is  fastened  to  the  tooth  with 
oxyphosphate  of  zinc,  and  a 
piece  of   gold,  platinum    or 
piano-wire  is  passed  through 
the  tube  and  allowed  to  come 
in  contact  with  the  surface 
of  a  firm  tooth.     Should  the 
tooth  that    has    been    regu- 
lated move,  the  wire  may  be 

bent  so  that  the  tooth  may  be  restored  to  its  proper  position. 
Two  or  more  teeth  may  be  retained  in  the  same  manner. 
The  tube  may  be  attached  to  the  labial,  buccal,  palatine  or 
lingual  side  of  the  band,  according  to  the  requirements  of 
the  case. 

LENGTH  OF  TIME  REQUIRED  TO  RETAIN  THE  TEETH  IX 
THEIR  PLACE. 

Two  reasons  governing  the  time  required  to  retain  th«- 
plate  upon  the  teeth  are,  first,  the  age  of  the  patient; 
ond,  the  nature  of  the  operation.     The  time  cam 
definitely  stated  for  all  persons,  even  of  the  same 
condition  of  case;  an  approximate  period  only  can  1, 
In  young  and  healthy  persons,  in  whom  reconstruct 
tissue  is  rapid,  the  retainer  will  be  needed  but  a  compavat,  v, 
short  time      If  the  superior  or  inferior  arches  ha 


pids  and  molars. 


],;,,  IRREGULARITIES  OF  THE  TEETH. 

T1,,-  most  difficult  teeth  to  retain  are  those  that  have 
Urn  rotated  in  their  sockets.  The  difficulty  of  correcting 
tin-  tendenev  t"  return  to  their  original  positions  is  so  great 
that  the  retainers  must  be  kept  in  place  from  one  to  t\v«. 
years.  a,,,l ,,, -, -annually  even  longer  than  this.  The  operator 
will  have  t<>  use  his  best  judgment  as  to  the  proper  time  to 
remove  them.  The  number  of  teeth  being  moved  does  not 

;  the  time  re. jui red,  as  the  bone  is  as  rapidly  deposited  in 
,,ne  part  of  the  jaw  as  another.  The  health  of  the  patient  will 
have  e..nsiderahle  influence  in  the  time  required.  A  strong, 
ruliu-t  person  will  recover  from  the  operation  more  rapidly 
than  one  that  is  ana-mic.  The  retainer  should  remain  as 
loin:  as  eiremnstamvs  will  warrant,  when  a  model  should  be 
secure- 1.  Alter  the  lapse  of  not  longer  than  a  day  an  exami- 
nation should  be  made.  If  the  teeth  have  not  deviated, 
a  week  may  elapse  before  making  another  examination. 
Thaw  examinations  should  be  continued  until  the  operator 

•i-tied  that  the  teeth  are  secure.  If  the  teeth  should 
move,  the  retainer  must  be  replaced,  and  allowed  to  remain 
for  from  three  to  six  months,  when  it  can  be  removed  and 
anv  deviation  noted. 


INDEX. 


Age,  question  of,  in  regulation,  73,  90. 
Allan's  case  of  protruding  lower  jaw,  152. 
Alveolar  plates,  17. 

process,  absorption  during  regu- 
lation, 95. 

—  inferior,  18. 

—  superior,  17. 
—       processes,  36. 

Alveoli,  18. 

Alveolus,  of  temporary  teeth,  absorption 

of,  62. 

Antrum,  11, 12. 
Arch,  dental,  27. 

—  —      spreading,  128. 

—  high,   association    with   V-shaped 

and  other  arches,  58. 
-    saddle-shaped,  51,  56. 

primary    cause  of, 
57. 

—  typical,  of  American  woman,  28. 

—  vaulted,  40. 
V-shaped,  41,  51,  92. 

Arches,  of  idiots,  68. 

Austin,  127. 

Axle,  in  regulating,  99. 

Ballard,  40. 
Bennett,  103. 
Bicuspids,  24. 

importance    of   occlusion   ot, 

89. 

—  irregularities  of,  45. 

—  removal  of,  in  regulating,  93. 
Black,  109. 

Bridle   apparatus   for  protruding  teeth, 

Byrnes'  method  of  regulating,  116. 

Cartwright,  49,  53. 

Chinese,  teeth  of,  49. 

Coffin's  method  of  regulating,  131. 

split  plate  method,  123. 

Coil  spring,  in  regulating,  126. 

Coleman,  49. 

Coles,  53. 

Cooke,  impression  cups,  87. 

Crowns,  29,  38. 

—       moving,  140. 
Crypts,  37. 
Cuspids,  23. 

_      abnormal  position  of,  4,5. 

_       irregular  eruption  of,  44. 


Cuspids,  irregularities  of,  43. 

large,  33. 

—      temporary,  extraction  of,  63. 
—       importance  of,  60. 

Decay  of  teeth,  78. 

Deformities,  congenital  and  acquired,  51. 

—  from  arrested  dcvelopim-nt. 

50,  52. 
Dentine,  21. 
Development,  of  jaws,  arrested  in  i.li»t-. 

71. 

Down,  68,  71. 
Dwinell,  102. 

Elastic  force,  in  regulating,  107. 
Elasticity  of  metals,  112. 
Enamel,  20. 
Eruption,  of  teeth,  forced,  142. 

—         Matteson's  method,  1 1:'. 

_         order  of,  38. 

_         Talbot's  method,  143. 
Expansion  plate,  Coffin's,  ll'l. 
Extraction,  early,  irregularities  from,  62. 

Farrar's  cases  of  protruding  teeth.  1 1-. 

method  of  moving  crowns  and 

roots,  141. 

_          —       of  regulating,  114 
_          _       of  rotating  teeth. 

—  retainers,  157. 

—  triplex  system,  136. 
Fees,  80. 

Filling,  of  temporary  teeth,  6J,  OJ. 
Force,  application  of,  93. 

Guilford,  91. 

Guilford's  method  of  rotating  teeth.  1- 

Heredity,  relation  to  irregularities,  45 

Idiots,  constitutional  irregularities  of,  69. 
_     irregularities  of  teeth  of,  68. 

vaulted  arch  of,  40.^ 

Impression  cups,  84,  85,  87 

_         of  lower  ja" 
Impression*  of  mouth  and  jaws,  8. 
__         how  to  take,  82,  83. 

Incisors.  --• 

—  central,  4-. 

_       pulling  out,  134. 
inferior,  irregularities  of.  9- 


161 


1  •;•_• 

lagton,  lrr*jrulsriti«»  of,  43. 

—  Utrl 

Ifi'lon*.  firth  of,  49. 
lrrl.nl 


INDEX. 


.  , 

iution»i,  of   toon, 

«9. 

_  correction  of,  relation  of 

•gr  to,  90. 

<-ti"l>'jry,  SI- 

from  arrested  develop- 
ment, 50. 

_  —       contact,  45. 

_  _  early  extraction, 

02. 

—  retention  of  tem- 

porary    molars, 
60. 

—  retention  of   tem- 

porary teeth,  58. 
heredity  ami,  I  >. 
—  rinniimt  teeth,  33. 

of  teeth  of  idiots,  68. 
of  temporary  teeth,  HI. 
fpecial  forms  of,  135. 

Jaekferew,  compound,  102. 

in  rt>(fulntin>r.  HC'. 
of  Lee  and  IJennett,  103. 
Jaw,  lower,  impreMion  of,  84. 
—    protrusion  of,  68. 

—  pruirnat>p>iiv 

—  Mddle.«haped,  56. 

—  dupe,  changed  by  thumb-sucking, 

41. 

—  *pper,  protrusion  of,  65. 

cause*  of,  fifi. 
Ja««.   contraction   of,   interfering   with 

tpeeeb,  78. 
—     imprewiono.  -:'. 

irregularitic*    of,    from    arrested 
development,  50. 
of  idioU,  69. 

Ktafdey.  53,  54.  6s. 

Stapler  '»  cam-  of  protruding  teeth,  145. 
retainer    for  anterior    teeth. 

IM. 

L*«r,  in  refnlating  and  moving,  87. 
I.«K»lure»,  in  regulating,  111. 

MeTullom,  102. 


children,  jaws  of,  71. 
Ma«iir,  band.  111. 


Ma««on.      . 

•»«'!  method  of  forced  eruption, 

Maiilla,  Inferior,  14. 

protrunion  of,  l.,j. 


Maxilla,   inferior,  protru.-i I.   Allan's 

case,  152. 

—  superior,  9. 

Maxillary     development,     irrc^ulariiii-> 

Iron),  50. 

Mechanical  forces  in  regulating,  97. 
Membrane,  peridental,  20,  30. 
Metal*,  elasticity  of,  112. 
M  iriorophalous  children,  jaws  of.  7  I . 
Modeling  compound  impression-.  M. 
Models,  how  to  make,  85. 

—  mounting,  86. 

—  study  of,  88. 

study  of  teeth  by  the,  79. 
Molare,  25. 

—  importance  of  occlusion  of,  89. 

—  irregularities  of,  45. 

—  temporary,    causing    irregulari- 

ties, 60. 
extraction,  causing 

irregularities,  63. 
Mouth,  impressions  of,  82. 
Mummery,  49. 

Nichols,  49. 

Occlusion,  79. 

—  anterior,  failure  of,  65. 

—  not   retaining  anterior  teeth. 

154. 

Pain,  in  regulating,  76. 

Patrick  method  of  regulating,  113. 

Piano-wire  in  regulating,  125. 

Plane,  inclined,  in  regulating,  100. 

Plaster  impressions,  82. 

Plates,  retentive  after  regulation,  77. 

—      with  gold  bands,  156. 
Pressure,  in  regulation,  76. 

—  steady  and  intermittent,  77. 
Process,  malar,  12. 

—  nasal,  12. 

—  palatine,  13. 
superior  alveolar,  17. 

Pulley,  in  regulating,  99. 
Pulp  of  teeth,  21. 

Regulation,  age  for,  73,  90. 

application  of  force  in.  '.i:>. 

—  coil  spring  for,  126. 

—  elastic  force  in,  1117. 

—  inclined  plane  in,  100. 
jack-screw  in,  102. 
late.  7  I . 

lever  in,  97. 
lijra Mires  in,  111. 
mechanical  forces  in,  !»7. 
methods  of,  113. 

Byrnes',  116. 

Coffin's,  121. 

Farrar's,  111. 

Patrick's,   IIM. 

Talbot's,  126. 


INDEX. 


163 


Regulation,  of  individual  teeth,  131. 
piano-wire  in,  125. 

—  pressure  in,  76. 
proper  time,  72. 

pulley,  wheel  and  axle  in, 
99. 

—  rapid,  95. 

—  removal  of  teeth  for,  90. 

— •          retention  of  teeth  after,  153. 

retentive  plates  after,  77. 
• —          screw  in,  101. 

wedge  in,  104. 
Retainers,  Farrar's,  157. 

—  Magill's,  157. 

—  Richardson's,  155. 

—  Talbot's,  159. 
Retention,  length  of  time  for,  159. 

of  teeth  after  regulating,  153. 
plate,  154. 

—  prolonged,  irregularities  from, 

58,  60, 

Richardson's  retainers,  155. 
Roots,  29. 

—     moving,  140. 
Rotated   teeth,    difficulty   of   retaining, 

160. 

Rotating  teeth  in  sockets,  135. 
Rotation  of  teeth,  75. 

—  —      Farrar's  method,  135. 
_  —      Guilford  138. 

—      Talbot's       —      139. 
Rubber  bands,  in  regulating,  107. 

Saddle-shaped  jaw,  56. 

Salter,  34. 

Screw,  in  regulating,  101. 

Septa,  dental,  19. 

Shepard,  44. 

Speech,  interfered  with  by  contraction  of 

jaws,  78. 
Stellwagen,  68. 

Talbot's  method  of  forced  eruption,  143. 

—       regulating,  126. 

—       rotating  teeth,  139. 

—  retainer,  159. 
Teeth,  absence  of,  34. 

—  anatomy  of,  20. 

anterior  impression  cups  for,  87. 

—  arch  of,  27. 

—  crowded  and  irregular,  90. 


Teeth,  crowns  of,  29,  38. 

—  cuspid,  4:'.. 

—  decay  of,  7*. 

—  description  of,  21. 

—  etiology,  31. 

—  examination  <•• 

—  forced  eruption  of,  14L'. 

—  im-ixirs.   1L',  43. 

—  irregularities  of,  33. 

—  occlusion  of,  27. 

—  of  idiots,  irregularities  of,  68. 

—  permanent,  20,  33,  34,  36. 

—  physiological  changes  of,  "5. 

—  physiology  of,  20. 

—  position  of,  29. 

—  prehistoric,  36. 

—  protruding,  145. 

—  Farrar's  case*,  14  v 

—  Kingsley's  owe,  14.">. 

—  regulation  of.    See  Jityulaliun. 

—  removal  of,  in  regulating,  90. 

—  retention  of,  58. 

after  regulating. 

—  roots  of,  29. 

—  rotated,  difficult  to  retain,  160. 

—  rotating,  in  sockets,  135. 
-    septa  of,  19. 

—  sockets  of,  18. 

—  supernumerary,  34. 

—  temporary,  20,  25. 

—  —         cleansing   and    filling 

of,  62,  63. 

—  —        extraction  of,  39. 

_  _  irregu- 

larities from,  62. 

—  —         irregularities  of,  33. 

—  time  for  removal  of,  63. 

—  wisdom,  35. 
Thumb-sucking,  31,  40,  41,  56. 

and  V-shaped  arch,  53. 

Tomes,  34,  35.  38,  52. 

Van  Marter,  36. 

Wedge,  in  regulating,  104. 
Wheel,  in  regulating,  99. 
White,  68. 
Wilmarth,  71. 
Winchell,  35. 
Wire,  piano.  1L'.">. 


NOV 


BIO' 


orm  L9-40«-5,'67(H2161s8)4939 


